LEE CHU MING, MARTIN AND OTHERS v. A PERMANENT MAGISTRATE, EASTERN MAGISTRACY AND ANOTHER

HCAL 1396/2020

[2020] HKCFI 2028

IN THE HIGH COURT OF THE

HONG KONG SPECIAL ADMINISTRATIVE REGION

COURT OF FIRST INSTANCE

CONSTITUTIONAL AND ADMINISTRATIVE LAW LIST NO 1396 OF 2020

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J U D G M E N T

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A.   Introduction

1.  This case raises important questions relating to the necessary balance between (a) protecting the basic rights of the individual and (b) the needs of law enforcement authorities to prevent, detect, investigate and prosecute crime.  It arises in the context of judicially issued search warrants permitting search and seizure of information and data stored in mobile digital devices, such as mobile phones, of the sort which are now carried and used by almost every person in Hong Kong.

2.  On one side, many would find it difficult to imagine a more intrusive invasion of privacy than the search of a personal computer, including a mobile phone.  The scale and variety of the material stored and accessible makes comparison with traditional storage receptacles unrealistic. On the other side, the advent of information technology and the popular use of mobile phones also present new modes for criminal activities to be conducted or evidenced.  Hence the need for the balance.

3.  With leave granted by Hon Coleman J on 4 July 2020, the Applicants bring these judicial review proceedings to challenge the issue of a total of 8 search warrants dated 26 June 2020 (“Search Warrants”), issued by the 1^st Respondent, a Permanent Magistrate at the Eastern Magistracy (“Magistrate”), on the application of police officers under the command and responsibility of the 2^nd Respondent (“Commissioner”).

4.  On 4 July 2020, as extended on 10 July 2020, Hon Coleman J also granted an interim injunction to restrain the Commissioner from executing the Search Warrants, until the determination of the application for judicial review.

5.  With the benefit of written skeleton submissions provided by the parties in advance of the hearing, the substantive application for judicial review was heard by two judges on 13 August 2020.

6.  The Applicants were represented by Mr Robert Pang SC and Mr Albert NB Wong, of Counsel.  The Magistrate takes a neutral stance in these proceedings, and her attendance was excused.  The Commissioner was represented by Mr Johnny Mok SC and Mr Mike Lui, of Counsel, and Mr William Liu DLO(C)(Ag) of the Department of Justice.

7.  This is our Judgment.

B.   Factual Chronology and the Search Warrants

8.  The basic factual chronology is not in dispute, and it is only necessary to set it out in brief form.  (We can deal later with some of the other factual evidence adduced by the parties.)

9.  On 18 April 2020, the Applicants were arrested by officers of the Hong Kong Police Force (“Police”) and charged with incitement knowingly to take part in unauthorized assemblies and/or organising and knowingly taking part in unauthorized assemblies.  The Applicants were amongst 15 persons arrested on the same day for connected matters.  The charges relate to unauthorized assemblies which took place on 18 August 2019, 1 October 2019 and 20 October 2019 (though not every Applicant faces a charge in respect of every unauthorized assembly). In addition, the 2^nd Applicant was charged for making announcements on 30 September 2019 and 19 October 2019 of two public processions objected to by the Commissioner.

10.  The arrests led to prosecution of the Applicants, whose cases were brought before a magistrate on 18 May 2020. On 12 June 2020, transfer bundles were served on the Applicants’ solicitors relating to the transfer of the case to the District Court.

11.  It had originally been expected that transfer might have taken place at a Magistrates’ Court hearing on 15 June 2020, but in the circumstances that some of the defendants to the charges indicated they might wish to take further legal advice and possibly challenge the intended transfer, the matter was adjourned.  However, subsequently, those defendants confirmed that they would not place any obstacle in place of transfer, which therefore occurred on 15 July 2020.

12.  The criminal proceedings came before the District Court for mention on 30 July 2020.  A further hearing has been fixed for 18 September 2020, for mention on an issue not relevant to this judicial review.

13.  However, subsequent to the service of the transfer papers on the Applicants’ solicitors on 12 June 2020, the Applicants were also served on 26 June 2020 with the Search Warrants in respect of mobile telephone and other electronic devices owned by each of them, and which (with the exception of the mobile phone of the 5^th Applicant, whose device had been seized earlier) had been taken from them and held by the police since the date of arrest, 18 April 2020.

14.  The Search Warrants were obtained, as is entirely typical, on the ex parte application of the Police.  They were sought and issued under section 50(7) of the Police Force Ordinance Cap 232 (“PFO”).  Section 50(7) provides:

(7)  Whenever it appears to a magistrate upon the oath of any person that there is reasonable cause to suspect that there is in any building, vessel (not being a ship of war or a ship having the status of a ship of war) or place any newspaper, book or other document, or any portion or extract therefrom, or any other article or chattel which is likely to be of value (whether by itself or together with anything else) to the investigation of any offence that has been committed, or that is reasonably suspected to have been committed or to be about to be committed or to be intended to be committed, such magistrate may by warrant directed to any police officer empower him with such assistants as may be necessary by day or by night—

(a)  to enter and if necessary to break into or forcibly enter such building, vessel or place and to search for and take possession of any such newspaper, book or other document or portion of or extract therefrom or any such other article or chattel which may be found therein; and

(b)  to detain, during such period as is reasonably required to permit such a search to be carried out, any person who may appear to have such newspaper, book or other document or portion thereof or extract therefrom or other article or chattel in his possession or under his control and who, if not so detained, might prejudice the purpose of the search.

15.  The Search Warrants are all dated 26 June 2020, were all issued by the Magistrate, and are in similar terms.  Those terms are:

SEARCH WARRANT

IN THE MAGISTRATE’S COURT AT EASTERN MAGISTRACY

HONG KONG

To each and all of the Police Officers of Hong Kong

INFORMATION has this day been laid before the undersigned, a magistrate of Hong Kong, on oath by [Police Officer’s name etc], Hong Kong Police, that there is reasonable cause to suspect that there is in a building or place, namely the following digital device (“Digital Device”): -

Descriptions	Seized from	TEPE No:
[device]	[person]	[number]

certain document(s) or article(s), namely, the digital contents of the Digital Device or any portion thereof or extract therefrom, which are likely to be of value (whether by itself / themselves or together with anything else) to the investigation of the offences, namely, (1) Organizing an Unauthorized Assembly, contrary to Section 17A(3)(b)(i) of the Public Order Ordinance, Cap.245, Laws of Hong Kong and (2) Knowingly Taking Part in an Unauthorized Assembly, contrary to Section 17A(3)(a) of the Public Order Ordinance, Cap.245, Laws of Hong Kong, that have been committed / is reasonably suspected to have been committed / about to be committed / to be intended to be committed*.

You are herewith empowered to enter the said building or place, namely the Digital Device, and to search for and take possession of the said article in any formats, including all digital contents of the Digital Device.  Officers executing this search warrant will keep the Digital Device sealed for 7 days from the date of service of this warrant for any aggrieved party to institute legal proceedings to establish their claim of legal professional privilege, otherwise at the expiry of the stipulated time, the Digital Device will be unsealed and examined.

Dated this 26^th day of June 2020

Magistrate

(* delete as appropriate)

16.  An application was later made, on 2 July 2020, to the Magistrate for a hearing to be conducted inter partes to set aside or vary the Search Warrants.  But, on 3 July 2020, the Magistrate declined to conduct any hearing on the basis that she lacked jurisdiction.  She did so without entertaining argument as to whether she had jurisdiction.

17.  The Applicants’ applications for leave to apply for judicial review and for interim injunctive relief were made the following day, 4 July 2020.

C.   Grounds of Review and Relief Sought

18.  Before dealing with other aspects of the factual matters, it is helpful to provide some context by identifying the intended grounds of judicial review and the relief sought by the Applicants.

19.  The Applicants’ application for leave to apply for judicial review primarily seeks an order to quash the Search Warrants, as well as various ancillary orders.

20.  The specific relief sought includes:

 (1)  an order of certiorari to quash the Search Warrants;

 (2)  a declaration that the seizure of a smart phone upon arrest for the purpose of accessing its digital contents must be followed by an application for a search warrant “without unreasonable delay”;

 (3)  an order of mandamus that the Applicants’ smart phones be returned to them;

 (4)  a declaration that the Commissioner must inform the owner of a smart phone of the intention to apply for a search warrant over the contents of the smart phone in order to facilitate an inter partes hearing;

 (5)  an order of certiorari to quash the decision of the Magistrate refusing to hear the applications to set aside or vary the Search Warrants;

and, alternatively to the above,

 (6)  an order of mandamus that the Magistrate proceed to hear the applications to set aside or vary the Search Warrants.

21.  There are four intended grounds of review:

(1)  the Search Warrants were issued ultra vires, because they lack particularity, are oppressive in scope, and provide a licence to ‘fish’ (“Ground 1”);

(2)  the retention of the mobile devices without warrant was beyond a reasonably necessary time (“Ground 2”);

(3)  there was a failure to inform of any application for the Search Warrants, when there were no circumstances justifying secrecy and immediacy (“Ground 3”);

(4)  the Permanent Magistrate was wrong to decline jurisdiction (“Ground 4”).

22.  Mr Pang also submits that the principles of law put forward by the Applicants in this case are not radical.  Those principles include, he says: (1) the right to have a process detrimental to one’s interest to be conducted without unreasonable delay; (2) the entitlement to be given prior notice of the charge against him and the right to be heard and an opportunity of meeting that charge; and (3) the right to see – on the face of the warrant – the proper circumscription of what are otherwise extremely intrusive powers that the world has never seen before.

23.  In due course, and leaving aside the unhelpful hyperbole, each of the grounds and submissions can be considered in turn.  But, it can also be borne in mind that Mr Pang emphasises that the particular relief sought, and the grounds of judicial review, relate specifically to the factual circumstances where the Police have already seized a mobile device from an arrested person before the Police seek a search warrant to gain access to the information and data on that mobile device.

D.   Applicant’s Evidence

24.  In addition to the affidavit from a solicitor which led the original application for leave to apply for judicial review, and the application for interim injunctive relief, each of the Applicants has filed an affidavit or affirmation in support of the application for judicial review.

25.  Each of the Applicants sets out the circumstances surrounding his arrest and the seizure of his mobile device(s).  Each of them also broadly identifies the information stored on the device in various applications.  As might be expected, each of them identifies that his device contains a great volume of personal emails and messages, personal contact information of people with whom he is in contact, his location data, saved passwords to accounts such as email accounts, and personal photographs and videos.  Many of the devices are Apple products, where the functions of the device are linked also to other Apple products such as laptop and iPad, via an Apple account.  None of the Applicants has given consent to anyone to unlock his phone/device, and each of the Applicants says that he has no intention to reveal the relevant unlocking password or code.

26.  The 1^st Applicant (“Mr Lee”) was the chairperson of the Hong Kong Democratic Party from 1994 to 2002, and remains a member.  He says he often uses his mobile phone to communicate with other members of the party on matters of political sensitivity.  Mr Lee is also a Senior Counsel, and frequently uses his mobile phone for work purposes communicating with solicitors, junior counsel, other counsel and third parties.  Mr Lee has made a claim for legal professional privilege (“LPP”) over the mobile phone.  He says the mobile phone contains notes, documents, and draft documents produced by him on instructions.  Therefore, he would have the greatest difficulty if he had to describe every single communication, note, or event since he first started using WhatsApp, email, or other applications that may have stored information that may involve LPP (unless given specific parameters).  Mr Lee gives recent examples, citing information in the public domain, of his involvement in cases which he describes as being of a certain sensitivity given the current political climate, and which are ongoing.

27.  The 2^nd Applicant (“Mr Ho”) was previously an elected member of the Legislative Council and District Council, and has been actively involved in the work of political party in various human rights non-governmental organisations.  Mr Ho is also the former chairperson of the Democratic Party from 2006 to 2012, and remains a member. Mr Ho is the current chairperson of the China Human Rights Lawyers Concern Group, and has been since 2006.  He says he uses his mobile phone often to communicate with other members of these groups on matters of political sensitivity.  Mr Ho is also a solicitor, and frequently uses his mobile phone to communicate with lay clients (as well as concerned friends and family members), members of his firm, Counsel, solicitors acting for other parties and third parties appointed.  Mr Ho has made a claim for LPP over the mobile phone.  Like Mr Lee, Mr Ho says his mobile phone contains notes, documents, and draft documents produced by him on instructions.  Therefore, he would have the greatest difficulty if he had to describe every single communication, note, or event since he first started using WhatsApp, email, or other applications that may have stored information that may involve LPP (unless given specific parameters).  Mr Ho also gives recent examples, citing information in the public domain, of his involvement in cases which he describes as being of a certain sensitivity given the current political climate, and which are ongoing.

28.  The 3^rd Applicant (“Mr Sin”), was previously the vice-chairperson of the Democratic Party until 2012, and is now the treasurer and a member of the central committee of the party, responsible for managing the day-to-day operation of the party and frequently discussing strategies, funding and expenses of the party.  Mr Sin says many of the discussions within the political party are very sensitive on various political, social and economic policies.  Mr Sin is also an elected District Councillor, and uses his mobile phone to communicate with citizens, and other members of civil society, on matters of what he calls political sensitivity or to discuss matters with his fellow councillors on matters which he says carry a certain degree of sensitivity and confidentiality.  Further, though not a lawyer, Mr Sin has also made a claim to LPP over his mobile phone.  The claim is based on regular communication with various legal practitioners, in particular Mr Ho and Mr Lee.  As a person with considerable IT experience, Mr Sin also expresses his concerns over phone hacking technology and how the Commissioner might conduct the inspection and examination of arrested persons’ mobile phones and digital devices.

29.  The 4^th Applicant (“Mr Au”) was previously a legislative councillor and district councillor.  He was responsible for the daily operation of his own office at both Councils, often communicating with staff and other cooperating parties, including high-level government officials, all matters which he considers to be of high public interest, sensitivity and confidentiality.  He has also often used his mobile phone to communicate with citizens and other members of civil society on matters which he says are matters of sensitivity. Further, though not a lawyer, Mr Au has made a claim to LPP over his mobile phone.  The claim is based on his regular communication with various legal practitioners, including in relation to previous alleged criminal matters which he has faced, and his involvement in other judicial review proceedings which he has brought.

30.  The 5^th Applicant (“Mr Yeung”) was the chairperson of the Hong Kong Democratic Party from 2002 to 2004, and remains as a member.  Mr Yeung has also served on the central committee and executive committee for various periods since then.  He says he often uses his mobile phone to communicate with other members on what he describes as matters of political sensitivity.  Unlike the other Applicants, Mr Yeung’s mobile phone was seized from him on 28 February 2020, on his arrest for knowingly taking part in an unauthorized assembly on 31 August 2019.  Mr Yeung subsequently learned from ‘unused materials’ that his mobile phone had been searched pursuant to a search warrant dated 4 March 2020.  That search warrant is not the subject of these proceedings, which instead relate to the subsequent Search Warrants dated 26 June 2020.  Mr Yeung has not made a claim to LPP.

31.  Though each of the Applicants complains in his affidavit or affirmation that he has yet to be assured that the tamper-proof exhibit bag containing his device has not been unsealed and the device has not been unlocked, we think that complaint is unfair in the context of the existing interim injunctive relief obtained at their instigation.  In any event, in the Commissioner’s evidence, it has been confirmed that the Police were fully aware of the injunction granted on 4 July 2020, and on 10 July 2020, and have fully complied with it.  Therefore, with the exception of Mr Yeung’s mobile phone (which had been previously unlocked on 12 March 2020), none of the devices the subject of the Search Warrant has been unlocked and searched (or, in the case of Mr Yeung’s device, further searched).  All devices remain sealed (or re-sealed), and are kept by the investigation unit pending the determination of this judicial review.  There is absolutely no reason not to accept that evidence as being true.  We accept that the Search Warrants are yet to be executed, precisely because of the interim injunctive relief granted.

E.   Commissioner’s Evidence

32.  The Commissioner has adduced affirmation evidence from (a) a Superintendent (“Mr Chan”) serving in the Regional Crime Headquarters of the Hong Kong Island Region of the Police and (b) a Chief Inspector of Police (“Mr Cheung”) serving at the Digital Forensics Investigation Section (“DFIS”) of the Forensics and Training Division, Cyber Security and Technology Crime Bureau (“CSTCB”) of the Police.

33.  Mr Chan’s evidence focuses on the detail of the circumstances in which the Search Warrants were applied for and issued, and responds to some allegations in the Form 86 (including the allegation of unreasonable delay).  Mr Chan also explains why it is in the interests of justice to proceed with the digital forensics examination as soon as possible.  Mr Cheung explains from a technical perspective certain key steps and features in the digital forensics examination process (including password unlocking and data viewing), and the connected importance of starting the examination as soon as possible.

34.  Mr Chan says that the digital content in seized mobile phones may contain information which is relevant and of value to the Police’s investigation, and it is in the interests of justice for the Police to complete investigation, and to do so as early as practicable.  He says it is common and also a trend for protesters, especially those taking up the role of organisation or actively inciting others to take part in unauthorized assemblies, to use their mobile phones as the major means of communications in furtherance of their objectives.  Hence, Mr Chan says it is only reasonable for the Police to suspect that the digital content stored in mobile phones would add evidential value to the investigation.

35.  Mr Chan emphasises that at no time have the Police had any malicious agenda, including but not limited to deliberately infringing arrested persons’ privacy rights for irrelevant purposes.  The Police concentrate only on the investigation of relevant crimes committed or suspected to have been committed, and identify and obtain relevant and necessary information.  Mr Chan also emphasises that the search of digital contents is always subject to the “restrictions” of relevance and reasonableness, and agrees with Mr Cheung’s explanation (see below) as to why it is difficult and inadvisable for certain search conditions, parameters or protocol to be imposed at the time of the application for a search warrant, given the difficulties in predicting where and how relevant data may be stored.

36.  Further, Mr Chan says, the investigation unit would carefully consider if the arrested person’s mobile device may add value to the ongoing investigation by containing information relevant to the crime under investigation and, bearing in mind the potential intrusion into privacy interest, would attempt to strike a balance between necessity for the purpose of the investigation and proportionality.

37.  Mr Chan explains the timetable leading from the arrest of the Applicants on 18 April 2020 to the seeking and issue of the Search Warrants on 26 June 2020.  Essentially, in light of the claims to LPP and a desire to take a consistent stance as regards expected numerous applications for similar search warrants, the Police considered it necessary to adopt a standardised approach and format and to take specific legal advice from the Department of Justice.  This also required schedule adjustments for the three separate inspectors handling the criminal investigation work in respect of each of the three unauthorized assemblies.  Necessarily, this took some time.

38.  Mr Chan explains the Police’s general treatment of digital devices seized from arrested persons or suspects from the perspective of the investigation unit.  After seizure of the device, the investigation unit will isolate it from the available network(s) as soon as practicable.  In this case, following the arrest of the Applicants and seizure of the mobile devices from them, the SIM cards were removed, and each SIM card was packed together with the respective mobile device in the same tamper evident property envelope (“TEPE”).  The reasons to isolate the seized digital devices from available networks include: (1) preserving the integrity of the original data stored in the seized digital devices, and to protect them from unintended or automatic changes to the original data due to continuous connection to a network; and (2) to prevent arrested persons or suspects from remotely deleting, overwriting or otherwise changing the original data in the digital devices seized.

39.  After investigations have been completed, subject mobile devices will be retained as exhibits pending conclusion of any criminal proceedings, at the end of which the devices will likely be returned. However, Mr Chan says that the devices are not kept by the Police for causing any inconvenience.

40.  As to the individual complaints in the Form 86, Mr Chan says as follows.  Regarding the alleged lack of particularity of the Search Warrants, Mr Chan relies on legal advice that the investigation unit is only required to state the matters prescribed in section 50(7) of the PFO and this has been the Police’s practice.  Further, he says that imposing certain search conditions, parameters or protocol in search warrants is not feasible, as the investigation unit cannot be expected to identify exactly what and from where digital contents are to be retrieved for evidential purposes, without first having a cursory look at the context and the data image retrieved.

41.  As to the giving of advance notice of an application for a search warrant, Mr Chan identifies the concern that information presented to the magistrate for applying for a search warrant is capable of revealing the details and progress of ongoing investigation which should not be made known to the defendants, which might alert defendants or suspects to destroy evidence not contained in the seized mobile phones, or to tip off accomplices or other individuals who may also be involved in the relevant suspected criminal activity.  Such information is protected by public interest immunity as a class of documents.

42.  Mr Cheung speaks more from the technical or forensics side.  His starting point is the general principle as to the Police’s handling of digital evidence, being that digital forensics examiners should maintain data integrity as well as data authenticity, and should primarily ensure that data in the concerned digital devices is not contaminated.  To ensure data integrity and to prevent contamination, digital forensics examiners should avoid working with the original data.  Instead, they create exact duplicate copies through imaging of the original data, the data integrity of which is checked by calculating and assigning the ‘hash value’ of the subject data image.  The ‘hash value’ might be regarded as a digital fingerprint for files, being an unique numerical value processed through a cryptographic algorithm.

43.  By reference to certain computer forensics manuals, including one issued by the Association of Chief Police Officers, Mr Cheung identifies that imaging of the original data, and performance of digital forensics examination on the working copy of the data image, is an approach internationally acknowledged and practiced.  Mr Cheung also identifies the importance of extracting data from the entire file system of the concerned mobile devices, instead of a portion of data.  Extraction of the file system means to image the entire file system of a target digital device.

44.  Mr Cheung also identifies that whilst digital space has been compared with physical premises, the way in which data is stored in the digital space is in fact different.  The same types of data may be stored across different applications; for example, records of communications may be stored across many different types of communication applications as well as emails, texts, call records, and multi-media files.  Hence, imaging the whole digital device is necessary to allow a comprehensive forensic digital examination.  It is also important to defendants and suspects for the integrity of the original data in the digital device to be preserved.

45.  Mr Cheung cites various paragraphs of the Force Procedures Manual (“FPM”) to show that there are clear guidelines on how responsible police officers are to handle digital exhibits.  The FPM contains confidential information and is not open to public inspection, but certain disclosure is made for the purpose of these proceedings only.  Points of importance include the chain of evidence, maintaining the integrity and admissibility of any digital evidence, full records of observations and actions, limiting interaction to the bare minimum, and isolating devices from available networks as quickly as possible after seizure.

46.  As to the actual procedures on digital forensics examination performed by DFIS, Mr Cheung deals with them under the headings: (a) submission of digital forensics examination request; (b) registration of digital exhibits; (c) passcode unlocking and data imaging; (d) data viewing – scope subject to the yardstick of reasonableness; and (e) documentation of the digital forensics examination process.  The first two headings relate to the examination request from the investigating unit to DFIS, and ensuring the search warrant authorises both seizure and search, as well as proper recording of the handover process.

47.  As regards data imaging, Mr Cheung identifies the practical reality that digital forensics examination can only be carried out primarily by DFIS police officers (who are equipped with the necessary tools to do so).  It is, therefore, wrong to suggest – simply because the Search Warrants are addressed to “each and all of the Police Officers of Hong Kong” – that the Search Warrants offer a ‘blanket license’ for any and all police officers to conduct search of the digital content.  Nor is it possible to gain access to cloud data, because the mobile devices are isolated from the network upon seizure.  For that reason, it is also groundless to suggest that the search of digital contents may somehow facilitate a de facto system of surveillance, simply because emails and records of other electronic communications are often synchronised between devices.  All examination processes – covering passcode unlocking and data imaging, as well as data viewing – are performed in a signal shielded room of DFIS’s computer forensics laboratory with a view to preventing any signal interference which may contaminate the original data stored in the mobile exhibits.

48.  As to data viewing, the full forensics examination process including data viewing must be performed within the validity period of the corresponding search warrant, if necessary the extended period(s).  Mr Cheung says the viewing process is always subject to the yardstick of reasonableness, and a warrant authorizing Police’s search of digital content is never deemed by DFIS or generally a licence allowing indiscriminate search of digital contents.  Mr Cheung says, first, at the initial stage of data viewing the responsible digital forensics examiner would apply certain parameters or keywords based on information supplied by the investigation unit with a view to narrowing down the volume of relevant data.  Such parameters or keywords may be chosen with reference to the date, time and place in relation to the occurrence of the crime under investigation or name of involved individuals or accomplices. He points out the very practical need for the scope of search to be narrowed down given that, nowadays, digital devices generally contain a huge volume of data, perhaps containing over tens of thousands of messages as well as photographs within the short timeframe before and after the occurrence of the crime.

49.  But, secondly, Mr Cheung says it is rather impractical for specific conditions, parameters or keywords to be imposed for search of digital content because, without a cursory look at the original data or data image, it is impossible for a digital forensics examiner to tell what relevant or useful information the target digital device may contain for the purpose of narrowing down the scope of search.  He says that if specific conditions, parameters or keywords for search of digital contents are imposed, that may heighten the difficulties in identifying data from the digital contents relevant to the crime under investigation, which is not conducive to the due administration of justice, and may even create room for criminals to deliberately hide relevant information in their digital devices to frustrate Police investigation.  Indeed, Mr Cheung says, it may also be very difficult for the Police to identify an exact period of time for search of digital contents.

50.  Insofar as it might be thought that there is any conflict between those two points, Mr Cheung makes clear in his evidence that as there are quite a number of ways for the relevant data to be covered up or hidden by using different storage formats or applications, it is impractical for the Police to identify a scope of search with reference to certain keywords or surmise what types of applications or kinds of information should be searched in order to yield fruitful outcome, without an opportunity to have a cursory look through the target mobile device.  In other words, the use of some parameters or keywords is part of the cursory looking process, which itself may depend upon the choice of different techniques to be applied to different formats and applications.  It is on completion of that data viewing process that the investigation unit would select the case relevant materials for further investigation.

51.  Mr Cheung also deals with the contemporaneous documentation of the digital forensics examination process in a specific form known as “Pol 155”.  Digital forensics examiners are properly trained and guided in the completion of such forms, including as to the date and time of access to the target digital device or data image, as well as the data viewing results.  If subsequently necessary, the digital forensics examiner will provide to the investigation unit a formal witness statement in a form known as “Pol 154”, if certain information extracted from the inspected digital context is used as prosecution evidence.  Mr Cheung exhibits a copy of the “Pol 155” relevant to the search of Mr Yeung’s seized mobile devices under the previous search warrant (not the subject of these proceedings).  As an example of the process, that form shows the relevant data viewing session at DFIS’s laboratory lasted only 25 minutes, with 14 relevant WhatsApp messages retrieved for the investigation unit’s further consideration.

F.   Introductory Points

52.  As indicated above, the Applicants have sought to stress that the impugned practices of the Commissioner are only unlawful in relation to the seizure of, retention of, and access to mobile phones/devices already seized from arrested persons.  Therefore, the Applicants expressly accept there may be a need to preserve secrecy when a warrant is prepared prior to an operation turning overt, and that the sufficiency of particularity in a warrant can sometimes be satisfied quite easily, when for example the relevant items for seizure are in an otherwise empty warehouse.  But, Mr Pang submits that a search warrant which is sufficiently particularized for a warehouse scenario is not necessarily sufficiently particularized to provide the necessary safeguards in relation to a mobile phone.  So, he says, these proceedings should result in some future “lateral thinking” on the part of magistrates and the Commissioner – where it is in any event a requirement of law that every search warrant should meet the specific circumstances.

53.  Mr Pang also seeks to place the current consideration in an overall context, that the statutory provisions of section 50(7) of the PFO are to be read within the wider common law, with its constraints in line with Hong Kong’s constitutional regime.  As he puts it, section 50(7) provides the jurisdictional framework for a magistrate to issue a warrant which must still comply with the common law constraints.  Hence, he says, it is only a properly issued search warrant with sufficient particularity consistent with common law and constitutional principles which is able to authorize the entry, search, and seizure of the contents of a mobile phone.  What Mr Pang terms as “mere fulfilment of conditions of section 50(7)” will not suffice.

54.  Mr Pang makes these points primarily by reference to the Court of Appeal decisions in Keen Lloyd Holdings v Commissioner of Customs and Excise [2016] 2 HKLRD 1372 (“Keen Lloyd”) and Sham Wing Kan v Commissioner of Police [2020] 2 HKLRD 529 (“Sham Wing Kan”).  The detail of those cases, and the points of principle which may arise from them can be considered further, below.

55.  But in so far as Mr Pang’s submissions assert that the Commissioner has taken the position that the issue of the Search Warrants and the handling of the devices is unobjectionable merely because that is the way it has always been done, or is otherwise legitimised by consistency with previous unchanged practice, we do not think that is the Commissioner’s position.  Rather, the Commissioner says that the Police have acted in accordance with the law, which is to be found primarily in the statute.  We, therefore, accept that if the Applicants say otherwise, it falls to them to demonstrate the relevant illegality.

56.  For his part, Mr Mok stresses at the outset of his submissions what these proceedings are not about, namely the constitutionality of section 50(7) of the PFO, under which the Search Warrants were applied for and issued.  As he puts it, there is no systemic challenge as to either (1) the requirements actually provided for in section 50(7) with which the Police have to comply for the purpose of applying for a search warrant, or (2) the omission of other requirements from section 50(7).

57.  In the absence of any systemic challenge, says Mr Mok, the question for the court is whether the challenge is or can be meritorious in view of the requirements in section 50(7), as explained and applied in the case law.  On this basis, he says the Applicants’ challenge is fundamentally flawed, in particular on their Ground 1.

58.  By way of a broad description of them, Mr Mok’s submissions are that:

 (1)  what should be stated in the search warrant itself is a matter of construction of the empowering provision;

 (2)  in construing the empowering provision, the court should not rewrite it (as writing legislation is the function of the legislature);

 (3)  where the Applicants suggest certain conditions must be imposed or stated, the legal basis for that is not clear because the Applicants do not contend that section 50(7) requires those conditions to be imposed or stated;

 (4)  if, by necessary implication, section 50(7) requires any particular conditions to be imposed in a warrant, they should be;

 (5)  but the Applicants do not argue that their proposed restrictions on the scope of search or seizure should be imposed as a matter of necessary implication under the section;

 (6)  in any event, such an implication would be impermissible.

59.  As to the Keen Lloyd and Sham Wing Kan cases, Mr Mok says that the application or meaning of section 50(7) were not issues arising for determination in either case.  Indeed, Mr Mok stresses that there is no dispute in these proceedings about the proper construction of section 50(7) at all, so that the Applicants do not dispute – and cannot dispute – that the requirements in the section were complied with in the applications for the Search Warrants, and that the Magistrate did not err in considering that those requirements had been satisfied.

G.   Duty of Candour

60.  Though Mr Pang suggests that the issues raised by these proceedings are preferably dealt with holistically, there are of course four separate Grounds put forward by the Applicants which can and need to be dealt with separately (even if there may be some degree of overlap).  Mr Pang suggests that the analysis might usefully be conducted in ‘quasi-chronological’ order beginning with Grounds 2 and 3 (delay and ex parte application) before dealing with Grounds 1 and 4 (ultra vires and jurisdiction of the Magistrate).  However, we think it preferable to deal with the Grounds in the order in which they were originally presented.  In part, this is because it seems to us that the answer to the issue raised by Ground 1 may inform the appropriate approach to at least Grounds 2 and 3.  Ground 4, being an alternate, logically comes last.

61.  It is, however, convenient first to deal with a separate point relating to the duty of candour faced by a respondent to an application for judicial review, once leave to apply for judicial review has been granted.

62.  The relevant duty of the respondent is to cooperate with the court by making available all relevant facts and reasoning underlying the decision under challenge.  This is sometimes referred to as the duty on a public authority to respond to a judicial review application with its cards face upwards on the table.  The purpose of imposing such a duty of candour on a respondent is to facilitate the court’s process of evaluation as contemplated by judicial review.  In essence, the court seeks to match the duty on the applicant to adduce his evidence fully and candidly with the duty on the respondent to provide primary documents and explanations relevant to the challenge (subject, of course, to lawful exemptions).

63.  In this case, Mr Pang suggests that the duty of candour has not been met by the Commissioner.  In particular, Mr Pang says that there has not been any proper explanation as to the chronology of events, where the chronology is clearly engaged by Grounds 2, 3 and 4.  As Mr Pang puts it, the court would be assisted if it had the evidence as to why the Commissioner decided to hold onto the mobile telephones without applying for a warrant for two months, but then when the urgency had already dissipated he decided to accelerate the process to access the mobile phones without notifying the Applicants and without giving them an opportunity to set the Search Warrants aside.  So, Mr Pang invites us to draw an adverse inference against the Commissioner regarding unreasonable delay and the absence of justification not to inform the Applicants of the application for search warrants.

64.  We do not think this is a good point.  In our view, as briefly outlined above, the Commissioner has explained the chronology between the seizure of the mobile phones and the application for and issue of the Search Warrants.  Whilst the relevant period of time might have been longer than even the Commissioner would have preferred, time was taken in obtaining legal advice from the Department of Justice (“DOJ”), and in synchronising various steps across individual (but similar) investigations, so as to promote a consistency in approach.  It would be unfair to criticise the Commissioner for the time taken for the provision of legal advice by the DOJ.  Further, where claims to LPP had already been put forward, and where other legal challenges might reasonably have been anticipated, the Commissioner is not to be faulted for displaying some degree of caution in the approach.

65.  We also think that Mr Pang mistakes the chronology if his submission amounts to the suggestion that the Commissioner deliberately held onto the mobile telephones for two months without applying for the Search Warrants, but then claimed a sudden accelerated urgency in applying for and seeking to execute the Search Warrants.  The Commissioner’s evidence makes clear that that is not what happened.  Rather, time was taken before the Search Warrants were thought practically able to be obtained, and it was then stated that they would be executed if no proper challenge was actually made before the expiry of the stipulated time.  We do not think the Commissioner can fairly be criticised for taking the view that he was entitled to execute Search Warrants which had been obtained from the Magistrate, if no formal challenge was made to them prior to the time stipulated on the face of the Search Warrants for the challenge to be made.

66.  Mr Pang also submits that there was a failure to meet the duty of candour when the Commissioner’s evidence has not sought to “rebut” the evidence of Mr Sin relating to the potential use of particular digital forensics tools which might be used for the passcode unlocking process.  We think this is a bad point.  The precise details as to how data imaging might be performed, including how the passcode unlocking process might be performed, is not a point which is properly within the scope of the judicial review challenge in these proceedings.  In so far as it is of any interest at all, Mr Cheung has confirmed in his evidence that all digital forensic examinations are generally performed by DFIS and that the viewing process is conducted by police officers of both the investigation unit and DFIS.  Further, there is no sharing of any materials or information obtained through the digital forensics process with other departments or third parties, whether in or out of Hong Kong.

67.  In short, we do not think that the Commissioner has failed to meet any appropriate duty of candour in this case.  We do not think there is any adverse inference to be drawn against the Commissioner from the chronology, or (subject to the argument on Ground 3) from the decision to obtain the Search Warrants without prior notice to the Applicants.

H.   Keen Lloyd

68.  On behalf of the Applicants, Mr Pang contends that the Commissioner’s position fails to apply Keen Lloyd, by wrongly construing section 50(7) in a manner which apparently authorizes potentially radical interference upon what Mr Pang calls the arbitrary ticking of boxes.  It is, therefore, necessary to see what Keen Lloyd decided.

69.  First, it is to be noted that in Keen Lloyd the Court of Appeal was concerned with a constitutional challenge to certain provisions under the Organised and Serious Crimes Ordinance Cap 455 and the Import and Export Ordinance Cap 60, pursuant to which various search warrants were judicially issued.  It was in the context of such a challenge that the Court of Appeal noted that the protection of the right to privacy in Article 29 of the Basic Law and Article 14 of the Hong Kong Bill of Rights was against “arbitrary or unlawful” interference, search and intrusion.  So, the Court held that ascertainable measures enforceable in law must be in place to allow for a proportionate limitation of the right while at the same time providing adequate safeguards to prevent executive abuse.  Whilst the broad concept of arbitrariness in the context of the Basic Law forms the juridical basis for the applicability of the proportionality test, it is to be applied cautiously so that only a statutory provision which was manifestly disproportionate would be struck down as arbitrary.

70.  Nevertheless, more relevantly for present purposes, the Court of Appeal did examine the ‘judicial gatekeeping role’ inherent in the requirement of a judicial warrant as a prior authorization for searches.  At §64, the Court found “enlightening” to the application of the proportionality test the previously stated idea that court interference is to protect individuals from unjustified State intrusions upon their privacy.  That purpose requires a means preventing unjustified searches before they happen, not simply of determining, after the fact, whether they ought to have occurred in the first place.  This can only be accomplished by a system of prior authorisation, not one of subsequent validation.

71.  At §§71-72, it was recognised that the vetting of an application for a warrant by a judicial officer provides important safeguards against arbitrary interference with rights of privacy, the significance of prior scrutiny having been previously recognised and explained.  The Court reiterated the following passage, taken from the judgment of Stock V-P in Philip KH Wong, Kennedy YH Wong & Co v Commissioner of ICAC (No 2) [2009] 5 HKLRD 379 at §§47-49, as a sound reminder of the approach which should be adopted by every law enforcement officer in an application for a warrant, and every judicial officer in the consideration of that application:

[47] The starting principle is the inviolability of private premises from arbitrary intrusion. The right to security of one’s home and of the place in which one works is a right historically protected by the common law and now widely recognized in constitutional and other human rights instruments. It is therefore incumbent on every magistrate or judge to whom an application to permit such an intrusion is made to remind himself of the seriousness of the act which he is asked to authorize and not to permit the apparent simplicity of the procedure or the frequency with which it is invoked to devalue its significance. The duty upon him has been described as “a high duty… to protect individual citizens from arbitrary infringements of their liberties, as well as a responsibility to facilitate the conviction of the guilty in the interests of the whole of society.

[48] The fulfilment of this duty means that the task must be approached judicially; in other words, the judicial officer must apply his mind to the individual circumstances of the case and exercise his own judgment. He must act within the boundaries of his powers as prescribed by the statute pursuant to which the application is made and, if an intrusion is, within those boundaries, justified by the facts ascertained by him, he should ensure that the intrusion authorized goes no further than is reasonably necessary for the permissible objective and that the parameters of the authorization are sufficiently clear on the face of the warrant, so that the person executing the warrant and the person upon whom it is served knows what is and what is not permitted.

[49] Where it is intended to search premises of a solicitor’s firm or of counsel’s chambers or where otherwise there is cause for a particular belief that the material sought is likely to include privileged information, that fact must be disclosed by the applicant to the magistrate. That is because there is a duty to disclose any fact that is material to the exercise of the power to issue a warrant, and the importance of legal professional privilege is such that the likely presence of privileged material in the place to be searched is self-evidently a material fact. …’

72.  The Court also endorsed the point that the purpose of the requirement that a warrant be issued by judicial officer is to interpose the protection of a judicial decision between the citizen and the power of the state.  The judicial officer’s function is to satisfy himself that the particular circumstances exist so as to fit the legislative right created, which authorizes a policeman or other executive officer of the state to enter upon a person’s premises, search his belongings and seize his goods.

73.  Earlier in the decision, at §§39-44, the Court introduced its point about the significance of judicial gatekeeping in issuing a warrant, albeit that was specifically in the context of the discussion which followed on constitutionality.  The Court pointed out that:

Subject to the overriding need to preserve the integrity and effectiveness of criminal investigations, it is inherently repugnant to our administration of justice to reach a judicial decision without affording the party affected any reasonable opportunity to contest the same.  Thus, it is implicit in the judicial nature of the warrant issuing process that the matter should be dealt with judicially, including the right to entertain an inter partes application for setting aside an ex parte warrant on the limited grounds.

74.  That is why, the Court held at §§40-41, judicial officers issuing the warrants have the power to entertain an inter partes application to set aside the ex parte warrants, albeit only on the limited grounds discussed in P v Commissioner of ICAC (2007) 10 HKCFAR 293.  Hence, up to the time when the warrants were fully executed, the applicants in that case could have applied to the courts for the setting aside of the warrants.

75.  First, it might be noted that there is emphasis on the overriding need to preserve both the integrity and the effectiveness of criminal investigations (echoing the same point made by the Court of Final Appeal).  Second, in the context of the argument in the current proceedings, it can be seen that the Court of Appeal in Keen Lloyd appears to have been considering an inter partes hearing to set aside warrants already obtained ex parte, rather than suggesting that there could or should be an inter partes hearing to decide whether or not warrants should be issued at all.  The clear implication is that the Court of Appeal thought the subsequent inter partes hearing, dealing with the challenge to the warrants obtained ex parte, would be sufficient to afford the affected party a reasonable opportunity to contest the warrants.  Subject to the further argument on Ground 3, we agree.

76.  Nor is there any suggestion in Keen Lloyd that the Court of Appeal was expressing any view or comment, even obiter, seeking to change or develop the approach laid down in the previous authorities, such as the Philip KH Wong case.  Mr Pang acknowledges in his submissions that he is seeking an ‘extension’ of Keen Lloyd, but based on the principles in Keen Lloyd.

I.   Sham Wing Kan

77.  Mr Pang says that the Sham Wing Kan case provides an overview of issues raised by the technology of mobile phones, and why the law must adapt.

78.  One of the matters established by Sham Wing Kan, at §§162-166, is that a magistrate can issue a warrant under section 50(7) of the PFO to authorise a search of the digital contents of a mobile phone, by treating the mobile phone as a separate ‘place’ for which a specific warrant should be obtained, and if the other requirements in section 50(7) are satisfied.  Giving a purposive construction to section 50(7) in respect of a search of a mobile phone as a place, the electronic data or files contained in it or a portion thereof or an extract therefrom can be regarded as “documents”.

79.  The case, however, was not directly concerned with section 50(7) of the PFO, but rather section 50(6) relating to the power to conduct searches incidental to an arrest.  It was in that context that the Court traced the evolution of the common law principles of search incidental to arrest, and later engaged in the proportionality analysis.

80.  Nevertheless, Mr Pang refers in particular to what he describes as the overall tone and effect of the judgment to be found in §105:

“Though the Court was not concerned with the power of search incidental to arrest in Keen Lloyd, in our view the general considerations discussed therein on the importance of safeguards by way of prior judicial scrutiny apply equally to a search of the digital contents of a mobile phone even in the context of a search incidental to arrest. As will be discussed below, a warrant can be obtained under Section 50(7) for the search of the digital contents of a mobile phone. Given the engagement of the rights protected under BOR 14 and BL 30 and the potentially high privacy interest of the digital contents stored in a mobile phone (which in many cases would be even higher than the privacy interest engaged in a search of private premises), we hold that even in the context of a search of such materials incidental to an arrest a warrant should be obtained before a search unless it is not reasonably practicable to do so. In processing an application for such warrant, a judicial officer must bear in mind the judicial gatekeeping role discussed under Section B3 in the judgment of Keen Lloyd.”

81.  Indeed, we note that the Court, at §112, recognised that mobile phones have evolved, from being simply telephones available to a few who could afford them, into multi-functional mini-computers used regularly by the vast majority.  At §§113-114, the Court commented:

113.  We no longer use mobile phones simply as telephones. We regularly use them to conduct many aspects of our daily life. We use them as instantaneous communication tools, cameras, voice or video recorders and players, calendars, diaries, albums, televisions, maps or newspapers. We use them for emails, social media, the internet, and millions of apps covering all aspects of our life. We even use them to conduct our bank or financial affairs. As Roberts CJ observed in Riley at p.2484, mobile phones are now such a pervasive and insistent part of daily life that “the proverbial visitor from Mars might conclude they were an important feature of human anatomy”.

114.  In terms of privacy interest, three important characteristics arising from the use of a mobile phone distinguish it from other objects that might be kept on an arrestee’s person: (1) the vast amount and unique nature of the personal information stored in it; (2) storage of such information on “cloud” accessible by the mobile phone; (3) the portability and accessibility of such information.

82.  At the same time, the Court also recognised, at §§131 and 133, that the advent of information technology and the popular use of mobile phones also present new modes for criminal activities to be conducted (and, we would add, evidenced).  Since what may be illicit communications are often conducted electronically, the digital data stored in the mobile phones of criminals are of high probative value in the proof of their involvement in those crimes.  Further, the law should recognise the new challenges presented by the use of mobile phones as instruments of crime and the legitimate need for law enforcement officers to search such phones in appropriate circumstances with appropriate safeguards.

83.  Though Mr Pang has referred to §§182-185, in particular to the Court’s acceptance that the common law in Hong Kong on mobile phone search upon arrest should develop by reference to the concept of reasonable practicability in which due regard is paid to the proportionality requirement in terms of intrusion into privacy interest by a search for law enforcement purposes, the Court made clear it was striking the balance at that point (i.e. the point of arrest).  The Court stated in terms at §184 that a police officer cannot search the contents of a mobile phone of an arrested person without warrant unless it is not reasonably practicable to obtain a warrant under section 50(7) before doing so.

84.  But the Court did also accept, at §185, and in line with its earlier comments, that given the potentially great privacy interest and volume of data stored in a mobile phone, the privacy interest engaged in a search of a mobile phone is potentially higher than a search conducted of private premises.

85.  It was specifically in the context of a warrantless search of a mobile phone that the Court identified that there should be adequate safeguards to protect the arrested person against arbitrary and unlawful interference: see §§187-188 and §§197-200.  In the context of a search of the digital contents of a mobile phone, the problem does not lie in the lack of legitimate law enforcement objectives for such a search.  Rather, the real problem stems from the potentially large amount of private and possibly sensitive data (which does not fall within the legitimate scope of search) stored in the phone alongside the information and data which fall within the legitimate scope of such search.  That is why there must be the adequate safeguards.

86.  One safeguard is to confine warrantless searches to situations where it would not be reasonably practicable to obtain a warrant before the search.  Others include that the scope and purpose of the search must be truly incidental to the arrest in question, that is the police officer must have a reasonable basis for having to conduct the search immediately. Even then, the officer should limit the scope of the detailed examination of the mobile phone’s digital contents to relevant items by reference to the criteria of being necessary (1) for the investigation of offence(s) for which the person was suspected to be involved, including the procurement and preservation of information or evidence connected with such offences, or (2) for the protection of the safety of persons (including the victims of the crime, members of the public in the vicinity, the arrested person and the police officers at the scene).

87.  A further safeguard would be achieved by way of documentation of the purpose and scope of the warrantless search, through a police officer making an adequate written record of the search as soon as practicable after the performance of the search.  A copy of the written record should be supplied forthwith to the arrested person, unless doing so would jeopardise the ongoing process of criminal investigation.

88.  It was held that those safeguards would ensure that such intrusion into privacy as occurred is not boundless, and would be confined to “cursory inspection for filtering purposes”.

89.  Also, at §201, the Court recognised that a police officer would have to conduct at least a cursory examination of the contents of a mobile phone in order to filter materials.  As the Court put it (our emphasis added):

Admittedly, since a police officer would have to conduct a cursory examination of the contents of a mobile phone in order to filter out materials outside the scope of relevant data and information, some minor intrusion on the privacy interest in the irrelevant materials is inevitable. However, such intrusion is inherent in any search of mobile phone, whether with or without warrant and irrespective of how the criteria for warrantless search is set. Ex hypothesi a search involves the differentiation of relevant information from irrelevant information. Even in the context of a search of private premises for physical (as opposed to electronic) evidence, a law enforcement officer would have to briefly go through items which have no relevance to the purpose of the search before disregarding the same. Thus, some intrusion of privacy arising from a cursory inspection cannot be avoided once it is accepted that the search of a mobile phone for evidence or information for the purpose of criminal investigation is legitimate.

90.  Importantly for present purposes in the current proceedings, the Court also recognised, at §206, that the search could be subject to effective supervision by way of after-the-event judicial review, and that way there would be adequate and effective safeguards against abuse and that the permissible warrantless search would be no more than necessary for the legitimate law enforcement objectives incidental to the arrest.  We think the position is a fortiori where there was a search performed with a warrant, so where the judicial gatekeeping process has been engaged, but where there could nevertheless also be after-the-event review.

91.  Further, in the context of the arguments in the current proceedings, it may usefully be noted that in Sham Wing Kan the Court of Appeal rejected the idea that section 50 of the PFO was a comprehensive code that displaced the common law: see §§49, 72 and 103.

92.  Hence, Mr Pang submits that the case shows that even prior judicial warrant has the requirement of common law constraints in line with the Hong Kong constitutional regime, including the constitutional regime of proportionality.

J.   Ground 1: Ultra Vires / Lack of Particulars

93.  It is well-settled that the power to search has always been regarded as an exceptional power, to be exercised only under certain justifying conditions.  A search warrant is a document issued by a person in authority under power conferred in that behalf authorising the doing of an act which would otherwise be illegal.  Entry and search of premises and the seizure of targeted articles would otherwise attract tortious liabilities in trespass and conversion, and unlawfully interfere with citizens’ right to privacy.  One relevant justifying condition is that the object of the search be specified by reference to a particular offence.  This is part of the balancing exercise struck between the public interest in the investigation and prosecution of crimes and the proper measure of protection to persons affected by a warrant.

94.  Indeed, this is one of the reasons why the court insists on strict compliance with the statutory conditions for a warrant, so as to give effect to that balanced legislative purpose.  But what is sufficient to be conveyed about the offence in question in a given case may vary with the nature of the offence.  In each case, it is necessary to apply the principle that the warrant should describe the nature of the offence so as to indicate the bounds of the search, and to assess the sufficiency of what is provided from the point of view of those reading it.  The question posed by this Ground 1 is whether that was done.

95.  We note that Ground 1 is based upon the allegation of ultra vires alone.  There is no contention that the court should somehow adopt a Wednesbury unreasonableness test in scrutinising the Search Warrants. The court is not asked to determine, for instance, whether any reasonable magistrate would have decided not to impose any of the suggested restrictions or conditions.

96.  Obviously, it will not suffice simply to make a general contention that the Search Warrants “could have been”, or even “should have been”, more specific.  It is necessary, therefore, to be careful to consider what the actual legal basis is for impugning the Magistrate’s exercise of judicial discretion in issuing the Search Warrants without imposing the now advocated specifications or restrictions.

97.  When pressed during the hearing, Mr Pang clarified that his submission is there should have been greater specificity or search protocols on the face of the Search Warrants, not because the terms of section 50(7) either expressly or by necessary implication required that specificity, but because it was a requirement of the common law.  Therefore, when the Magistrate issued the Search Warrants without meeting that requirement of the common law, she exercised her powers in a way which was ultra vires.

98.  In this context, Mr Pang produced at the hearing an additional authority, R v Secretary of State for the Home Department, ex parte Pierson [1998] AC 539, as an example of a case where the common law fills gaps left open by the wording of the statute, sometimes referred to as “the spirit of legality” or the principle of legality.  At 588, Lord Steyn referred to what he regarded as “the best modern explanation” of the principle of legality in the following passage taken from Cross on ‘Statutory Interpretation’ 3^rd Ed pp 165-166:

Statutes often go into considerable detail, but even so allowance must be made for the fact that they are not enacted in a vacuum. A great deal inevitably remains unsaid. Legislators and drafters assume that the court will continue to act in accordance with well-recognised rules … Long-standing principles of constitutional and administrative law are likewise taken for granted, or assumed by the courts to have been taken for granted, by Parliament. Examples are the principles that discretionary powers conferred in apparently absolute terms must be exercised reasonably, and that administrative tribunals and other such bodies must act in accordance with the principles of natural justice. One function of the word ‘presumption’ in the context of statutory interpretation is to state the result of this legislative reliance (real or assumed) on firmly established legal principles. There is a ‘presumption’ that mens rea is required in the case of statutory crimes, and a ‘presumption’ that statutory powers must be exercised reasonably. These presumptions apply although there is no question of linguistic ambiguity in the statutory wording under construction, and they may be described as ‘presumptions of general application’. … These presumptions of general application not only supplement the text, they also operate at a higher level as expressions of fundamental principles governing both civil liberties and the relations between Parliament, the executive and the courts. They operate here as constitutional principles which are not easily displaced by a statutory text.

99.  Lord Steyn described that explanation as the intellectual justification of the often quoted proposition that “although there are no positive words in a statute requiring that a party shall be heard, yet the justice of the common law will supply the omission”.  By reference to other authority, Lord Steyn said that other illustrations of the operation of the principle of legality are to be found in the common law principles of procedural fairness requiring disclosure, and other procedural safeguards provided by the common law.

100.  Mr Pang submits that once it is accepted that the present case is governed by the common law, the remaining principles should be trite.  He refers to Chapter 5 of Feldman on ‘The Law Relating to Entry, Search and Seizure’.  It might, at once, be noted that that book was written in 1986, and was plainly not focused on circumstances relating to access to digital information and data of the sort with which we are concerned now, nearly 35 years later.  But the statements of broad general principle probably still hold good.

101.  By reference in particular to §5.01, Mr Pang says that:

 (1)  The requirement for the police officer to apply for a warrant gives another person, namely a magistrate, a chance to check on the need for the search.

 (2)  The warrant allows the occupier of the premises to be searched to satisfy himself that officers who arrive and demand to be admitted are acting lawfully – which cuts down the risk of misunderstandings, violence and criminal charges which often follow, and makes the job of the police easier.

 (3)  It should indicate the limits of the powers of the officers, circumscribing their discretion and clarifying their rights.  The warrant should be in a form which will enable it to perform these functions, by showing that its issue was an intra vires act by a proper authority and by indicating the limits and purpose of the officers’ authority.

 (4)  A warrant which does not do these things will fail to fulfil one or more of the purposes expected of it.

102.  Further, Feldman at §5.05 states that the principles to be extracted from the cases are: (1) the warrant must show that it has been issued by the proper authority; (2) it must show that the preconditions to its issue have been fulfilled; (3) it must be directed to proper people; (4) the place to be searched must be clearly identified; (5) the article sought must be sufficiently indicated; (6) the offence in respect of which the warrant is issued must be sufficiently indicated; and (7) any other matters necessary to the validity of a particular warrant must be shown, and some others are desirable.

103.  Mr Pang submits that the Commissioner is effectively asserting that only categories (1) to (3) of the previous paragraph are required.  We do not think that is a correct description of the Commissioner’s position.  Indeed, on the face of the Search Warrants themselves, the other categories are plainly addressed.  What the Commissioner is actually saying is merely that the Police seek to state in search warrants, for which authorization is sought from a magistrate, those matters which are required to be stated.

104.  We agree that it is settled law that what should be stated in the search warrant itself is a matter of construction of the empowering statutory provision: see, for example the Philip KH Wong case at §§62-66, 84-85.  The analysis looks at what the statutory provision requires, either expressly or by necessary implication.  It must also be correct that in construing the empowering provision, the court should not rewrite it (because writing legislation is the function of the legislature).  Therefore, “constitutional submissions” are immaterial where no systemic challenge is pursued.  Of course, if on the proper construction, by necessary implication, section 50(7) requires any particular conditions to be imposed in a warrant, they should be, but the Applicants do not argue that their proposed restrictions on the scope of search or seizure should be imposed as a matter of necessary implication under the section.

105.  It might also be noted that the Court of Appeal in the Philip KH Wong case did not find it correct or justified in principle to impose restrictions or conditions to protect even the undeniable and absolute right of LPP.  In so deciding, the Court stressed, at §91, the lack of an exact or certain basis for such implication.  It also held, at §§60-61, that the magistrate could decide not to issue the warrant if he was not satisfied that there would be a mechanism in place to protect privilege, or the magistrate could in the exercise of judicial discretion impose conditions to achieve the protection.  We agree.

106.  As to the objects of the search, Mr Pang refers to Feldman at §5.20, which states that where the warrant itself authorizes seizure, there must be guidance contained in the warrant as to the articles which the officer is entitled to seize.  If no guidance is given, the officers are left an unbridled discretion to seize more or less anything, and as a general principle the law opposes the grant of uncontrolled discretions to administrative offices such as investigators.  But the passage also goes on to state that the warrant cannot give exhaustive guidance, since an officer who enters premises lawfully under a search warrant is sometimes empowered to see some other things not directly covered by the warrant.  Nevertheless, the warrant must at least set out what the officers are trying to achieve and how they are to set about it.  A warrant which fails to do that is no help to the occupier of premises or to the officer in working out the limits of his powers, and may be liable to be quashed as being unreasonably general.

107.  This seems to be at the core of Mr Pang’s submissions.  His focus is on the sufficiency of the indication or description of the articles sought, and the sufficiency of the description of the offence in respect of which the warrant is issued.  Mr Pang submits that there is a lack of sufficiency.

108.  In particular, as regards the description of the offence, Mr Pang points out that the Search Warrant does not refer either to the time or the place of the stated unauthorized assemblies.  He says that the lack of any temporal reference at all, even to the date of the alleged offence(s), let alone to the parameters of any relevant search of digital data on the mobile phone, is a fundamental flaw.  In fact, he says that the Search Warrants appear to give authority to search all digital contents, without limitation of any sort.  Whilst Mr Pang accepts that any relevant parameters need not necessarily be precise, he says that there must be some sufficient parameters.

109.  Mr Pang identifies that one of the problems of insufficiency in the stated parameters of the authorized search is that the greater the power afforded to the police officer who executes the Search Warrant, the greater the risk of abuse of that power.  Mr Pang submits that it is unsatisfactory for the Commissioner in effect to say “trust me”.  However, as we made clear during the hearing, we do not think the relevant considerations relate to matters of trust.  What is at issue are matters of legality; a complaint that a magistrate has acted ultra vires is not a complaint which gives rise to questions of trust or breach of that trust, but whether the magistrate has acted lawfully, within the magistrate’s powers (however they are described and proscribed).

110.  We accept that where it is alleged that an offence was committed on a particular day, it would be at least good practice (but often probably a requirement) that the date of the alleged offence is indicated in the description of the offence on the face of the Search Warrant. As it happens, on the particular facts of this case, though the dates of the alleged offences were not stated, the dates were well known to and would have been clear to the Applicants.  This arises in part from the chronology, and in part from the references in the top right-hand corner of each of the Search Warrants.

111.  As already set out above, the Search Warrants in this case were in fact obtained and served on the Applicants after the commencement of criminal proceedings against them, and even after the transfer bundles had been served on them (for the purpose of transfer to the District Court).  In those circumstances, the Search Warrants were actually served on the Applicants by service on their instructed solicitors (the same solicitors acting for them in these proceedings).  That service was by way of a letter headed with a Police Reference number, enclosing a copy of the relevant Search Warrant (with an identified writ number) stated to have been obtained in relation to the digital contents of the client’s mobile phone (with a stated TEPE number).  The letter also invited contact with a named Police Officer in the event of any query.

112.  The references in the top right-hand corner of the Search Warrants included the Information number, the Writ number and the Police Reference number.  As an example, the Search Warrant relating to Mr Lee’s mobile phone had the Police Reference number HKI RN 20000144.  That number is to be found in the top left-hand corner of the Brief Facts in the relevant criminal case, which document of course specifically identifies the allegations including by reference to location and time and date.  Therefore, in this case, there could have been no confusion or misunderstanding as to the date and place of the offences specified as those relevant to the investigation on the face of the Search Warrants.

113.  The remaining question is as to whether there should have been any temporal or other parameters set, by reference to keyword searches or other predictive coding.  If there are none, says Mr Pang, the search becomes a licence to fish or is arbitrary.

114.  Mr Pang relies on the principles he says can be derived from Keen Lloyd, at §58, as regards elements of arbitrariness, including that: (1) something lawful may nonetheless be arbitrary; (2) arbitrariness is to be construed broadly to include elements of inappropriateness, injustice and lack of predictability; and (3) the concept of arbitrariness has developed to embrace within it the concept of manifest or gross disproportion in addition to its traditional meaning of “capricious, unreasoned or without reasonable cause”.

115.  But those comments were made in the context of a constitutional challenge to a statutory provision, where the court was recognising that a high threshold must be crossed before a statutory provision can be struck down as arbitrary by reason of it being manifestly disproportionate.  As Mr Mok emphasises, in this case, there is no systemic challenge to the statutory provision found in section 50(7), so we do not think the broad view of what is or is not arbitrary underpinning the juridical basis for the applicability of the proportionality test in relation to articles of the Basic Law or of the Hong Kong Bill of Rights is of any particular help in the current analysis.

116.  Nor is there any force in the complaint about the reference to “all digital contents” in the authorisation for seizure on the face of the Search Warrants.  Mr Pang relies on the part of the Search Warrants which states (with his emphasis):

You are herewith empowered to enter the said building or place, namely the Digital Device, and to search for and take possession of the said article in any formats, including all digital contents of the Digital Device.  Officers executing this search warrant will keep the Digital Device sealed for 7 days from the date of service of this warrant for any aggrieved party to institute legal proceedings to establish their claim of legal professional privilege, otherwise at the expiry of the stipulated time, the Digital Device will be unsealed and examined.

117.  So, says Mr Pang, the authorisation for the seizure of “all digital contents” must be manifestly disproportionate.  Mr Pang says that a warrant authorising that search and seizure is authorising an arbitrary interference.  But that submission ignores the context in which the above paragraph is to be found.  Immediately before it is the other main paragraph of the Search Warrant, which states:

INFORMATION has this day been laid before the undersigned, a magistrate of Hong Kong, on oath by [Police Officer’s name etc], Hong Kong Police, that there is reasonable cause to suspect that there is in a building or place, namely the following digital device (“Digital Device”): -

[details of device]

certain document(s) or article(s), namely, the digital contents of the Digital Device or any portion thereof or extract therefrom, which are likely to be of value (whether by itself / themselves or together with anything else) to the investigation of the offences, namely, (1) Organizing an Unauthorized Assembly, contrary to Section 17A(3)(b)(i) of the Public Order Ordinance, Cap.245, Laws of Hong Kong and (2) Knowingly Taking Part in an Unauthorized Assembly, contrary to Section 17A(3)(a) of the Public Order Ordinance, Cap.245, Laws of Hong Kong, that have been committed.

118.  Excluding the words unnecessary to the specific case, that paragraph states:

there is reasonable cause to suspect that there is in the following [detailed] digital device (“Digital Device”) certain document(s) or article(s), namely, the digital contents of the Digital Device or any portion thereof or extract therefrom, which are likely to be of value (whether by itself / themselves or together with anything else) to the investigation of the [named] offences that have been committed

119.  On that basis, it seems to us that the description of the digital device and its digital contents are part of a composite description of the thing or things of which the Search Warrants authorized seizure (and search).  Stepping back, and as a matter of practicality, it is difficult to see how a police officer might seize only part of the digital contents of a phone, without seizing the phone itself.  It is also difficult to see how a police officer might seize the phone, yet somehow not seize and take possession all of its digital contents.  Hence, we do not think that the description of the digital device and its digital contents is arbitrary.

120.  It can also be noted that the particular words at the end of the paragraph on which Mr Pang relies specifically identify that it is the Digital Device which will be unsealed and examined.  That does not seem to us to mean, or to require, examination of all digital contents of the Digital Device (other than, perhaps, the “cursory glance” necessary to facilitate the focused search – see below).

121.  It is then necessary to look at what is the subject of the search.  We note that the Applicants themselves accept (through Mr Pang’s submissions) that it is of course the case that in every search scenario the “cursory glance” of all the contents is inevitable to ensure that the relevant evidence is obtained.  As Mr Pang says, the cursory inspection is for filtering purposes, and was held to be embraced by the common law principles in Sham Wing Kan at §206.  But, Mr Pang says what is at issue is that the Search Warrants expressly purport to authorize the search and seizure of all digital contents, not simply the unavoidable need to glance at the contents in order to identify whether a document comes under the category of relevance.

122.  This submission is difficult, for the practical reasons already identified.  Unless the Search Warrants expressly authorizes the search and seizure of all digital contents, it is difficult to see how the police officers executing them could lawfully take even a cursory glance of all the contents.  Yet, Mr Pang accepts that such a cursory glance is inevitable.  We agree that it is inevitable, as a law enforcement officer would have to go briefly through items which have no relevance to the purpose of the search before disregarding them, and if it is to take place it must be made lawful by the proper description of what is authorized on the face of the Search Warrants.  We also agree that some intrusion of privacy arising from a cursory inspection cannot be avoided once it is accepted that the search of a mobile phone for evidence or information for the purpose of criminal investigation is legitimate.

123.  But Mr Pang goes further to say that the use of keyword searches, filters and (in appropriate cases) predictive coding or artificial intelligence would enable the search to be conducted in a way that holds a proper balance between the need for effective investigations and the protection of the guaranteed rights of the individual.  He accepts that each case will involve different levels of difficulty in defining the appropriate terms of search and seizure, but that is why the warrant issuing process must be a flexible one, involving all relevant parties where possible. But, Mr Pang says, the authorization to search “all digital contents” may not be even rationally connected to the legitimate aim, let alone being necessary to accomplish that aim without imposing an unacceptably harsh burden on the individual (the Hysan test).

124.  The ultimate point made by Mr Pang is that such a warrant gives the Police licence to fish for anything of interest whether relevant to the statutory purpose or not, which is what renders the Search Warrants ultra vires.  We do not think that is correct.  There is no licence to fish.  The statutory purpose is set out on the face of the Search Warrant, which specifically requires – and, indeed, limits the authorization to – search of the portions or extracts of the digital contents of the Digital Device which are likely to be of value to the investigation of the specific named offences.

125.  Looking back at what Feldman at §5.05 says is required, it seems to us that the Search Warrants in this case have set out what the officers are trying to achieve and how they are to set about it, precisely because (contrary to the Applicants’ submission) the Search Warrants have addressed (a) the place to be searched, being the mobile phone/device (b) a sufficient indication of the articles sought, being those digital contents as may add value to the investigation, and (c) the offence in respect of which the Search Warrants were issued, being the allegations relating to unauthorized assemblies, the details of which were well-known to the Applicants.  On that basis, we think that the executing officers, and those affected by the Search Warrants, will be able to understand the object of the search and to comprehend the limits to the scope of the search which has been authorized.  This is achieved precisely by reference to the nature of the offence the object of the warrant being stated on the face of the warrant (supplemented by the cross-referenced materials), in a way which is both intelligible and sufficient to convey what those concerned with or affected by the warrant need to understand: see, for example, the decision of the High Court of Australia in Smethurst v Commissioner of Police [2020] HCA 14 at §27.

126.  It can also be noted that the absence of identifying a clear “limit” or the exact scope of relevant informational materials for search and seizure has been rejected as being a valid objection in other cases.  Primarily, this is because it is often impossible for the Police to determine the exact scope at the stage of investigation, and without conducting at least a cursory look at the digital contents of the mobile phone: see, for example, R(H) v IRC [2002] STC 1354 at §§28-40; R (Failseltex) v Crown Court at Preston [2009] 1 WLR 1687 at §§73-79; R (Cabot Global Limited) v Barkingside Magistrates’ Court [2015] 2 Cr App R 26 at §§33-40, 46; Y v Commissioner of ICAC [2020] HKCFI 161 at §§34-35; and Cheung Ka Ho Cyril Cyril v Securities and Futures Commission [2020] 1 HKLRD 859 at §§63-68.  Those decisions recognize the very real practical problems that would confront police officers conducting searches, not least where there may be wide-ranging and broad investigation, including of the timings and the pattern in the content of any communications between suspects.  It may be difficult, if not impossible, for an officer to specify a particular document which is relevant, which may be even more so in the context of information stored digitally.  It is recognized that it is not easy to see how search warrants could be satisfactorily narrowed by reference to specific documents, types of documents or other detailed description of the material that is sought.  Emphasis is also placed on the desirability of a construction leading to practical justice.

127.  We would also point out that the Applicants, quite properly, do not allege in this case that in obtaining the Search Warrants, it was the police’s intention to seek and search for or seize materials or information irrelevant to the investigation of the offences specified in the warrants.

128.  Mr Mok says that Mr Pang’s submissions in any event ignore direct authorities on the topic which identify a judicial consensus that ex post, or after-the-event, review is the preferred mode of control, when the reasonableness of the police’s actual conduct in search of the device comes under scrutiny, as opposed to the imposition of any ex ante search protocol, which is generally considered to be impracticable, and unsuited to the task of the authority issuing the warrant (in Hong Kong, a magistrate such as the Magistrate who issued the Search Warrants).

129.  Mr Mok refers to the decision of the Supreme Court of Canada in R v Vu [2013] 3 RCS 657.  One of the things recognised in the case, at §§44-45, was that there are numerous and striking differences between computers (including mobile phones) and traditional “receptacles”.  One difference is that all documents accessible in a filing cabinet are always at the same location as the filing cabinet, the same is not necessarily true of information that can be accessed through a computer.  But the main point for citing the Vu case is in its consideration, at §§53-61, as to whether authorizing justices should be constitutionally required to include such protocols in warrants authorising the search of computers or mobile phones.

130.  One of the interveners in the case submitted that, in addition to a requirement that searches of computers be specifically authorized by a warrant, the court should also find that these warrants must, as a rule, set out detailed conditions, sometimes called “ex ante conditions” or “search protocols” under which the search may be carried out.  It was argued that search protocols are necessary because they allow authorizing justices to limit the way in which police carry out their searches, protecting certain areas of a computer from the eyes of the investigators.  The opposition to that argument was that it was contrary to principle and was also impractical.

131.  The Supreme Court of Canada, through the unanimous judgment of the Court delivered by Cromwell J, treated computers in some respects as if they were a separate place of search necessitating distinct prior authorisation.  That is in line with Hong Kong authority.  But the Court was not convinced that the constitutional Charter also required that the manner of searching a computer must always be spelt out in advance.  As it was put, that would be a considerable extension of the prior authorization requirement and would be one that would not, in every case, be necessary properly to strike the balance between privacy and effective law enforcement.

132.  That conclusion was reached for two reasons, given at §§55-58:

 (1)  First, the manner of searches is generally reviewed after the fact.  That sort of detailed review with evidence and argument from both sides is better suited to developing new rules about how searches are to be conducted than is the ex parte procedure by which warrants are issued.  An ex post review of the reasonableness of a computer search in a particular case can signal to police how they should limit their searches in future cases.  Further, after-the-fact review may lead courts to set out specific rules according to which searches must be conducted.  Also, developments in the case law may spur legislative action aimed at tackling the issues more comprehensively.

 (2)  Second, requiring search protocols to be imposed as a general rule in advance of the search would likely add significant complexity and practical difficulty at the authorization stage.  At that point, an authorizing justice is unlikely to be able to predict, in advance, the kinds of investigative techniques that police can and should employ in a given search or foresee the challenges that will present themselves once police begin their search.  In particular, the ease with which individuals can hide documents on a computer will often make it difficult to predict where police will need to look to find the evidence they are searching for.  Indeed, computer files can be misnamed by accident, disguised by intention, or hidden altogether, leaving investigators at a loss to know in advance what sort of search will prove sufficient to ferret out the evidence they legitimately seek.  Attempts to impose search protocols during the authorization process risk creating blind spots in an investigation, undermining the legitimate goals of law enforcement that are recognised in the pre-authorization process.  These problems are magnified by rapid and constant technological change.

133.  It is also important to set out the conclusion of the Court stated at §61:

By now it should be clear that my finding that the search protocol was not constitutionally required in this case does not mean that once police had the warrant in hand, they had a licence to scour the devices indiscriminately. They were bound, in their search, to adhere to the rule that the manner of the search must be reasonable. Thus, if, in the course of their search, the officers realised that there was in fact no reason to search a particular program or file on the device, the law of search and seizure would require them not to do so.

134.  We think the same view is entirely apposite in Hong Kong.

135.  Similar points have been made by different courts in various other jurisdictions, within Canada or the United States.

136.  In the United Kingdom, it is also sufficient to specify the electronic devices in a search warrant, without specifying the underlying target electronic material (which may be spelt out in the search warrant application).  Nor is there any need to present any search protocol during the search warrant application.

137.  The current UK legal position can be seen in a Consultation Paper No 235 on Search Warrants, dated 5 June 2018, issued by the Law Commission.  There is no requirement for ex ante search protocols under UK law.  At §§10.18-10.23, the Law Commission stated:

 (1)  Search warrants specifying electronic devices are commonplace.  In such cases, a distinction may be drawn between the device specified on the face of the warrant and the underlying target material on the device.  The target material, instead, may be spelled out on the search warrant application before the issuing authority, rather than on the face of the search warrant.

 (2)  There have been a number of legal challenges to search warrants that specify electronic devices.  These have been unsuccessful, however, as the courts’ conceptual approach to electronic devices is that each of them is a single item rather than a container of separate items, like a filing cabinet with paper documents.  This approach is referred to as the ‘single item theory’.

 (3)  The device as a whole can be specified in the warrant, and the court will consider this to be a single item rather than a container of a number of things.  Therefore, a warrant can legitimately authorise the seizure of a computer or hard disk or mobile phone even though it may contain vast quantities of irrelevant material.

 (4)  If there are reasonable grounds to believe that there was incriminating material on the computer, tablet, smart telephone or similar device, then it may constitute relevant evidence, thereby properly forming the subject of an order under section 8 of the Police and Criminal Evidence Act 1984.  The fact that there may also be material that is irrelevant does not make the computer any less “material” which is likely to be of substantial value to the investigation, as well is likely to be relevant evidence.

 (5)  The courts have consistently held that a computer or hard disk is not a ‘container’ like a filing cabinet and must be regarded as a single object or thing for the purposes of a warrant application.

 (6)  Where a search warrant is applied for, the applicant is under a duty to make full and frank disclosure.  It is during this stage that the issuing authority should be satisfied that the statutory criteria for issuing the search warrant are met.

138.  Reference can also be made to Cheung Ka Ho Cyril v Securities and Futures Commission [2020] 1 HKLRD 859 at §§51, 75-94, where Chow J dealt with a submission that the warrants in that case were defective because the magistrates failed to include or set out a “protocol” in the warrants on how examination of the contents of the digital devices should be carried out by the SFC’s officers in order to protect the privacy of the applicants.  Chow J held that what is required to be included or set out in a warrant depends, ultimately, on the terms of the enabling statute. There is no overriding or overarching requirement for specificity outside what is mandated by the relevant statute authorising the issue of the search warrant.

139.  Chow J also specifically referred, at §§81-82, to the decisions of the Court of Appeal in Apple Daily Ltd v Commissioner of the ICAC (No 2) [2000] 1 HKLRD 647 at 674 and the Philip KH Wong case at §§69 and 86.  Further, at §§93-94, Chow J noted that, at the investigative stage, it is unlikely that the SFC would wish to confine the warrant to a particular document or documents, and seeking authorization to search for, seize and remove documents by reference to broadly defined classes or categories is neither unlawful nor unconstitutional.  Hence, he rejected the contention that the warrants were unlawful or invalid for want of specificity.

140.  But it is fair to point out that, when considering the “no more than reasonably necessary” third element of the proportionality 4-step test established in Hysan Development Co Ltd v Town Planning Board (2016) 19 HKCFAR 372, Chow J referred, at §55, to the evidence that during the search operation the SFC’s offices would, where possible, first carry out a preliminary examination of the digital devices found in the applicants’ premises using keyword searches to check whether they contained materials relevant to the investigations.  Devices which upon preliminary examination did not appear to contain relevant materials were returned to the applicants.  Where officers did not have time or opportunity to go through in detail all the emails (some of which appeared relevant) at the time of the search, the devices were seized.

141.  Further, at §56, Chow J identified in respect of the “fair balance” fourth element of the proportionality test that the SFC had all along made it clear that it was amenable to using keyword searches to identify relevant materials contained in or accessible through the digital devices and/or viewing the contents together with the applicants so as to minimise the chance of their personal or other information which was irrelevant to the SFC’s investigation is being viewed by its officers.  Further, disputes on relevance could be brought to the court for determination, with the disputed materials being sealed pending the court’s decision.

142.  Mr Pang relies on those passages as showing that the prior identification of appropriate keyword searches or other predictive coding at least could be achieved.  This might, he says, have achieved the fair balance.  That may be so, but the question still remains whether it must be done, and so whether it must be stated on the face of the Search Warrant, without which they are rendered unlawful and invalid.

143.  In this context, it can be noted that Cromwell J went on in the Vu case to make the following comments at §62:

Although I do not find that a search protocol was required on the particular facts of this case, authorising justices must assure themselves that the warrants they issue fulfil the objectives of prior authorisation as established in Hunter. They also have the discretion to impose conditions to ensure that they do. If, for example, an authorising justice were faced with confidential intellectual property or potentially privileged information, he or she might find it necessary and practical to impose limits on the manner in which a computer could be searched. In some cases, authorising justices may find it practical to impose conditions when police first request authorisation to search. In others, they might prefer a two-stage approach where they would first issue a warrant authorising the seizure of a computer and then have police return for an additional authorisation to search the seized device. This second authorisation might include directions concerning the manner of search. Moreover, I would not foreclose the possibility that are developing understanding of computer searches and changes in technology may make it appropriate to impose search protocols in a broader range of cases in the future. Without expressing any firm opinion on these points, it is conceivable that proceeding in this way may be appropriate in some circumstances.

144.  We think the position is the same in Hong Kong. Indeed, the Magistrate did impose a protocol to cater for the claims to LPP.  There may, in future, and as a result of decisions made on thorough after-the-event review with the benefit of argument by reference to actual circumstances, be developed the kind of experience which would permit magistrates broadly to adopt the approach suggested by Cromwell J on matters other than LPP.  However, whatever approach is adopted cannot require magistrates, who are unlikely to be technically trained, to have to engage in significant technical considerations.  In other words, whilst we accept that it may be within a magistrate’s powers to approve or require some search parameters in any given case, we do not think the exercise of the discretion not to do so renders the warrant as one issued outside the magistrate’s powers (assuming the warrant otherwise complies with the requirements of the statute).

145.  Mr Mok submits that the absence of ex ante search protocol or restriction as regards an electronic device (such as a computer or mobile phone) is anyway not inconsistent with the constitutional protection for privacy, for two reasons: (1) the authority to search a mobile phone is subject to the implied condition that the manner of search must be reasonable; and (2) the manner of search may be subject to judicial review after the fact.  As regards that review, if it is alleged that the Police conducted the search in an unreasonably wide manner, then the affected person can seek judicial review of the actual search of the device, and the ex post review can deal with the actual circumstances, and which would provide adequate and effective safeguards against abuse.

146.  We agree, and we adopt the approach set out in the Vu case at §61.  Though a warrant granted to Police to authorize seizure and search of mobile phones and similar digital devices does not have a search protocol, that does not mean that the Police are somehow given a licence to scour the devices indiscriminately.  They are bound, in their search, to adhere to the rule that the manner of the search must be reasonable.  Thus, if, in the course of their search, the officers realize that there is in fact no reason to search a particular program or file on the device, the law of search and seizure would require them not to do so.

147.  In conclusion, though we think it is open to a magistrate to approve or require search protocols in individual cases of authorization of search warrants, we do not think the failure to have required any protocol to have been applied to the Search Warrants in this case gives rise to any good ground of judicial review on the basis put forward in Ground 1.

K.   Ground 2: Retention of smart phones without warrant beyond a reasonably necessary time

148.  Mr Pang submits that once Sham Wing Kan is properly understood, and trite common law principles are applied, this Ground is also relatively simple.  Public law powers are to be exercised reasonably, which includes the exercise of them within a reasonable time.

149.  Mr Pang submits that, unless the phone itself is the relevant evidence, the Police can only seize the phone for the purposes of obtaining relevant evidence from its contents.  In most cases, it is reasonably practicable to obtain a search warrant, so that is what should be done before accessing the phone.  Where the time required for the preparation of an application for a search warrant is a matter of days, not months, Mr Pang says it is incumbent on the Commissioner to find out without unreasonable delay as to whether the mobile telephones contain evidence relevant to the investigation.  If the Commissioner does not know whether such material exists, he must find out, and do so by obtaining a valid warrant to assess the mobile telephone in question.

150.  But Mr Pang then criticises the Commissioner for the fact that no evidence has yet been adduced to show that the phones belonging to the Applicants actually contain such material.  He also refers to the evidence where Mr Chan stated that it is impossible for the Police to “surmise” whether a defendant’s or suspect’s mobile device may contain relevant or useful information, which can only be confirmed after the digital forensics examination process.

151.  We think Mr Pang’s reasoning is confused. By applying for the Search Warrants, and as is apparent from the face of the Search Warrants, the Police were asserting that there was a reasonable basis for believing that some of the information or data on the mobile phones would be of value to the relevant investigation into the specific offences mentioned.  Of course, whether that suspicion proves well-founded could only be confirmed after the digital forensics examination process.  But saying that it is not possible to “surmise” that the relevant mobile device contains useful information until confirmation after examination is not inconsistent.  Rather, it is a statement of the perfectly obvious.

152.  If Mr Pang’s criticism extends to saying that the Police have still failed to find out what is on the digital devices, that is an unreasonable submission the light of the fact that these proceedings have, including by the interim injunction, prevented to date the execution of the Search Warrants.

153.  Further, as we have already observed above, we do not accept that there was any failure to explain the time between the date of seizure of the mobile phones and the date of obtaining the Search Warrants. The Commissioner’s evidence is not seriously disputed, and is in fact indisputable.  So, we reject Mr Pang’s submission that the chronology cries out for an explanation but there is deliberately none.

154.  Mr Pang submits that there can be no objection to the declaration sought at relief (5) of the Form 86, that the seizure of a smartphone upon arrest for the purpose of accessing its digital content must be followed by an application for a search warrant “without unreasonable delay”.  But we do not think such a declaration is of any practical benefit.  What is or is not unreasonable delay will depend upon the particular circumstances of any case.  Though Mr Pang suggests that there has been unreasonable delay in this case, we reject that submission.

155.  We also think there is force in Mr Mok’s criticism of Ground 2, as being unclear as to precisely what legal basis is said to underpin the ground.  As he points out, there is no complaint of irrationality or Wednesbury unreasonableness, nor any allegation that the alleged delay was somehow ultra vires.

156.  We see no merit in Ground 2.

157.  Though Mr Pang accepts that it is not material to the disposal of the Grounds in the current proceedings, there is perhaps more force in his point that the necessity of keeping every phone until the end of the proceedings is doubtful.  We accept that ordinarily, where a copy has been taken of the data on the mobile phone, that copy would usually suffice so that the original data and the phone on which it was held might be returned.  However, that may also vary from case to case, and if seized objects become “exhibits”, they are generally not to be disposed of until the end of the trial.

158.  On a practical level, there is some force in the submission that any ‘chain of evidence’ concerns might be dealt with at an early stage in criminal proceedings, so that the parties might indicate whether admissibility of computer records data extracted from digital devices will be challenged.  If the contents of the phone, and the copy of those contents, are accepted as being accurate, then it may well be that the phone can be returned for the continued enjoyment and use by its lawful owner.  As Mr Pang says, that is simply a matter of reasonableness and common sense.  However, though a matter worthy of some comment, it is strictly beside the point on this judicial review, and we say nothing further on the point.

L.   Ground 3: Notice for a Contested Hearing for a Search Warrant

159.  On this Ground, Mr Pang refers to Article 10 of the Hong Kong Bill of Rights and Article 35 of the Basic Law.  He relies on the principle that it is ordinarily inherently repugnant to our administration of justice to reach a judicial decision without affording the party affected any reasonable opportunity to contest that decision.

160.  In particular, Mr Pang relies on what he says is the clear authority in Keen Lloyd, which he says echoes previous cases which identify the need for a balancing exercise to be carried out in advance of making an application, to see that steps taken are proportionate in the circumstances.  In Keen Lloyd at §38, the Court of Appeal said:

In our judgment, the question is not to be answered by looking for rules of the court providing for setting aside an ex parte order. A more fundamental answer lies in art 35 of the Basic Law and art 10 of the HKBOR. These provisions protected the right of access to courts and the right to a fair hearing in the determination of a person’s rights in a suit at law. Ex parte applications are restrictions of these fundamental rights and they are justified only to the extent it is proportionate to the legitimate need for having applications to be made on an ex parte basis. In the context of an application for warrants under the IEO and OSCO, whilst there is obvious need on the ground of secrecy to preserve the integrity and effectiveness of criminal investigations to justify an application to be made on an ex parte basis, we do not see any justification for excluding the possibility of an application to set aside on the limited grounds as discussed in P v Commissioner of ICAC, supra when there could be sufficient safeguard to secure the relevant materials or documents upon the service of the warrants pending the determination of an application to set aside. There should not be any difficulties in having such safeguards by way of placing the seized materials in locked premises and prohibiting any use being made of the same pending the determination of the application to set aside, see Apple Daily Ltd v Commissioner of the ICAC [2000] 1 HKLRD 595.

161.  Mr Pang also refers to Keen Lloyd at §§39-44, which (as touched on above) introduces the significance of judicial gatekeeping in issuing a warrant, and points out that, subject to the overriding need to preserve the integrity and effectiveness of criminal investigations, it is inherently repugnant to our administration of justice to reach a judicial decision without affording the party affected any reasonable opportunity to contest the same, at an inter partes hearing.

162.  Mr Pang submits that what is at issue is simply whether the relevant evidence can be preserved.  He accepts that in most cases the relevant materials cannot be preserved until after an ex parte hearing and at least the partial execution of the warrants, when seized materials can be kept aside.  But, as in this case, mobile telephones seized upon arrest are ordinarily immediately isolated from networks, so that no remote tampering can take place, and are then placed into TEPEs.  Therefore, the conditions allowing for a return to the basic principles of a fair hearing are already in place prior to the application for a search warrant.  That permits, or requires, an inter partes hearing of the application for the search warrant.

163.  In response, Mr Mok submits that it is implicit in the judicial nature of the warrant issuing process that the warrant is issued on an ex parte application, but the magistrate has the right to entertain an inter partes application for setting aside an ex parte warrant on the limited grounds defined in P v Commissioner of ICAC (2007) 10 HKCFAR 293 at §§44-51.  In doing so, he says, the balance is struck between the overriding need to preserve the integrity and effectiveness of criminal investigation on the one hand, and the affected person’s right of access to the court on the other.

164.  Keen Lloyd at §36, in following P v Commissioner of ICAC at §§44-51, describes the limits to the grounds upon which an application can be made to set aside a search warrant as being challenges regarding: (a) the legal limits for the grant of warrant; (b) the warrants were obtained by fraud or bad faith; or (c) oppression. But, the court cannot entertain challenges as to whether a case of reasonable suspicion has been established.

165.  Mr Pang submits that the Applicants in this case were entitled to contest the application for the Search Warrants on grounds that the terms were overbroad and therefore oppressive – ie. points (a) and (c) above.  He says those grounds do not engage any issue of public interest immunity, which is a red herring.

166.  But it is important that the shorthand adopted by the Court of Appeal in Keen Lloyd does not obscure what was intended by the fuller statement of principle given by the Court of Final Appeal in P v Commissioner of ICAC.  Dealing with the question as to what grounds may be entertained by the court in exercising the power to discharge or vary the order obtained ex parte, the Court of Final Appeal identified the first ground as, having regard to the proper interpretation of the provision under which the search warrant was authorized, the order is invalid as it goes beyond what is contemplated by the statute.  As to the ground of fraud, the Court of Final Appeal emphasised that a successful challenge on that ground would be “rare”.  Further, the discussion relating to oppression was because the subject of the statutory scheme in that case may have to spend a tremendous amount of time and incur considerable effort and expense, but even that heavy burden would not be sufficient to satisfy the high test of showing oppression.  What has to be established is that, having regard to what is involved for the subject, taking into account his circumstances, it would be oppressive for him to comply with the notice.  As the Court noted, “the circumstances in which this high test would be satisfied would be exceptional”.  That is clearly not the kind of oppression to which Mr Pang now wishes to allude; there is nothing oppressive in the burdensome sense for the Applicants to comply with the Search Warrants.

167.  Mr Pang further submits that, given that the Commissioner does not appear to contest that his powers of search must be circumscribed by relevancy, he cannot imagine how the investigating authorities could have objected in such a contested hearing to the imposition of prescribed parameters of search by reference to the time and nature of the offence.  But, we have dealt with this point above.

168.  In any event, it is clear from the evidence, and as a matter of common sense, that the issue as regards giving or not giving notice is not simply whether the relevant evidence can be preserved.  There are many other factors which come into play in deciding whether giving notice is either appropriate or necessary.  They have been identified in the Commissioner’s evidence (see above).  Amongst the various factors are potential concerns that advance notice will tip off persons under investigation as to how to deal with other evidence, or to inform accomplices or third parties who may act in a way which would frustrate or impede criminal investigations.

169.  The concern increases with the risk that information stored in remote databases, or in ‘the cloud’, might be remotely deleted or altered by the suspect or other persons having access to the remote data.  This point was specifically recognised in Sham Wing Kan at §124, where the Court of Appeal warned that the risk of remote access to the volatile digital content stored on cloud platforms by other users via other digital devices, pending the obtaining of a search warrant, should not be negated.

170.  It is also important that there is no confusion between (1) the situation where a search warrant has been obtained ex parte and executed, and challenges made to its issue and execution on the limited permitted grounds, and (2) the situation where notice has to be given even before an application such that there will necessarily be an inter partes hearing.  As Mr Mok points out, the Police’s concern is not that it will have to produce privileged documents, but that giving notice will alert suspects and accomplices to the need to conceal and/or destroy evidence.

171.  It is also important that there is no confusion between (1) what is necessary to make the issue of a search warrant legal or valid, and (2) the entirely different question as to whether the warrant was executed reasonably.  This case is concerned with the former question.

172.  Here, reference can be made to So Wing Keung v Sing Tao Ltd [2005] 2 HKLRD 11 at §37(2), where Ma CJHC (as he then was) stated:

I of course readily accept that in normal ex parte situations in civil proceedings, the party affected should have a right to be heard if that party wishes, particularly as ex parte orders are essentially provisional in nature: see WEA Records Ltd v Visions Channel 4 Ltd [1983] 1 WLR 721 at p.727D-E. O.32 r.6 is the statutory embodiment of this right. Equally, the fact that an ex parte order has been performed provides no reason to prevent the affected person from seeking to overturn its grant. For example Anton Piller orders may often already have been executed before a party seeks to set it aside. However, a search warrant is quite different in nature. It is not part of any ongoing process, or part of any lis between two or more parties. In procedures for the issue and execution of such warrants, occupiers have no right to be told at the stage of the application or before the warrant is executed of the grounds upon which the application has been made all the grounds upon which the warrant has been issued: see Inland Revenue Commissioners & Another v Rossminster Ltd & Others [10980] AC 952 at p.999.

173.  On the facts of this case, Mr Mok says that the Magistrate built two safeguards into the Search Warrants in relation to potential challenge.  One was the specific suspension of execution of the Search Warrants for a period of seven days to permit claims to LPP (and which time might also have been used, as it was tried to be used, for any other form of challenge).  The other was that the Search Warrant had to be fully executed before 26 August 2020, unless extended.

174.  Mr Mok also submits that the Applicants have not shown any prejudice caused by the Police having proceeded ex parte as usual.  We are not sure that the question of such prejudice is centrally relevant in these proceedings, but we agree that no prejudice has been demonstrated.  As Mr Mok says, there can be no suggestion that the Police will not make disclosure of the Search Warrants.  Clearly such disclosure has been given, along with the other materials relevant to the criminal proceedings.  Once the Search Warrants have been executed, the digital contents on which the prosecution will rely will also be disclosed.  Arguments as to admissibility, or whether such contents are covered by privilege, can and will be decided by the criminal court.

175.  We think there is no merit in Ground 3.

M.   Ground 4: Jurisdiction of the Magistrate

176.  Mr Pang submits that the law in support of this Ground has been covered by the other Grounds.  He refers in particular to §§38-44 of Keen Lloyd.  Mr Pang says that the Applicants went to great lengths to present an opportunity for hearing before the same Magistrate as had issued the Search Warrants, so as to try to avoid the very scenario in Keen Lloyd where the failure to do so was criticised.

177.  Mr Pang suggests that the “less than cooperative nature” of the Commissioner’s response, and the Magistrate’s refusal to hold an inter partes hearing, is even more inexplicable in light of the fact that the mobile telephones are in fact still sealed, and the time for execution of the Search Warrants has not yet expired.

178.  Mr Mok concedes that the Magistrate’s view that she had no jurisdiction to hear an application to set aside the search warrant is “probably erroneous”.  On the authority of Keen Lloyd, we think that her view certainly was erroneous.  But we agree that the Magistrate’s failure to entertain the application is academic, if the other challenges raised in Grounds 1, 2 and 3 have no merit.

179.  Indeed, in the Form 86, and in the original submissions supporting the application for leave to appeal for judicial review, the Applicants accepted that the proposed order of mandamus that the Magistrate proceed to hear the applications to set aside or vary the Search Warrants may not be necessary, depending on the court’s determination of the other grounds.

180.  As we have decided that Grounds 1, 2 and 3 do not have merit, there is clearly no point in requiring the Magistrate to hear again the same arguments.  Therefore, judicial review being a discretionary remedy, and even though we think the Magistrate erred in declining to hear the application, we would not grant any relief.

N.   Result

181.  The application for judicial review is dismissed.

182.  For the avoidance of doubt, we make clear that we have not addressed, nor have we made any comment on, the merits or detail of the claims made by the Applicants to LPP.

183.  We make a costs order nisi that the Applicants shall pay the Commissioner’s costs of the proceedings, to be taxed if not agreed, with certificate for two Counsel.  The order will become absolute after 14 days, if neither party applies within that period for the order to be varied.  Any variation application will be dealt with on paper.