5.  The applicant was born in 1925 and lives in Brighton. 6.  The applicant has been active in the peace movement since 1948 and has been a regular attender at public demonstrations since then. 7.  In 2005 the applicant began participating in demonstrations organised by Smash EDO. The object of Smash EDO was to close down the activities in the United Kingdom of EDO MBM Technology Ltd, a United States-owned company which manufactured weapons and weapon components and had a factory in Brighton. Serious disorder and criminality were features of a number of Smash EDO protests. Smash EDO protests therefore attracted a substantial policing presence. 8.  The applicant was twice arrested at Smash EDO demonstrations for obstructing the public highway but has never been convicted of any offence. 9.  In March 2010 the applicant made a subject access request to the police under section 7 of the Data Protection Act 1998 (see “Relevant domestic law and practice”, below) for information relating to him. Sixty‑six entries from nominal records for other individuals and information reports which incidentally mentioned him, concerning incidents between March 2005 and October 2009, were disclosed to him. Those records were held on a police database known as the “Extremism database”, which at the relevant time was under the responsibility of the National Public Order Intelligence Unit of the police (NPOIU). 10.  Most of the records related to demonstrations at the office of EDO MBM Technology Ltd but thirteen entries related to other demonstrations. They included, for example, the recording of his attendance at the Trades Union Congress (“TUC”) Conference in Brighton in September 2006; at a demonstration at the Labour Party Conference in Bournemouth in September 2007; at a pro-Gaza demonstration in Brighton in January 2009 and at a demonstration against “New Labour” organised by a number of trade unions in September 2009. In the great majority of cases, the information recorded about Mr Catt was his name, presence, date of birth and address. In some cases his appearance was also described. A photograph of the applicant taken at a demonstration in September 2007 was also disclosed to him in response to his subject access request. 11.  In August 2010 the applicant asked the Association of Chief Police Officers (“ACPO”) to delete entries from nominal records and information reports which mentioned him. In September 2010 ACPO declined to do so. They did not give reasons. 12.  On 17 November 2010 the applicant issued proceedings against ACPO for judicial review of the refusal to delete the data. He contended that the retention of his data was not “necessary” within the meaning of Article 8 § 2 of the Convention. Permission to seek judicial review was granted in March 2011 (see section B, below). 13.  In January 2012, HM Inspectorate of Constabulary published a report on undercover police operations designed to obtain intelligence about protest movements (see paragraphs 50 to 53 below). The report concluded that information was being unnecessarily retained in police records. Although the report was concerned with covertly obtained intelligence, it also led to an extensive review of the database covering overtly obtained intelligence and resulted in the deletion of a large number of nominal records and information reports. After that deletion process, the number of reports which mentioned the applicant was apparently reduced to two. 14.  Following the judicial review proceedings, the applicant wrote to the police to make a further subject access request. The police replied on 12 November 2015 stating:
“... the records are held to help UK policing manage a future risk of crime – of which [you] could be the victim. The records themselves should not and will not be disclosed [to you] for what are obvious reasons. An intelligence database loses all efficacy if it is not kept confidential.” 15.  In answer to a question asked by the Court when communicating the case the Government indicated that they had discovered four additional records mentioning the applicant in the database. They clarified that as a result, at the time the case was determined by the domestic courts there had in fact been six rather than two records in the database mentioning the applicant. 16.  Of the four additional records, two concerned references to the domestic legal proceedings by third parties. The Government indicated in their submissions that one of those has since been deleted. The other two referred to the applicant. One was dated 15 April 2011 and detailed the applicant’s presence at five separate events, not organised by Smash EDO, where there was a significant police operation and arrests occurred. The other was dated 19 July 2011 and related primarily to a third party but mentions the applicant’s attendance at an event which was not organised by Smash EDO. There is no indication of whether there was any police presence or arrests at that event. 17.  The Government stated that the police could not provide any explanation of why the reports were not disclosed previously. However, they were investigating the matter. They indicated that they had informed the Supreme Court and the applicant of the additional reports. 18.  In a witness statement dated 6 June 2011 prepared in the context of the proceedings introduced by the applicant before the High Court, the then National Coordinator explained the functions of the National Public Order Intelligence Unit (NPOIU) and the position as regards retention of data relating to the applicant. In his witness statement, the National Coordinator clarified that the material which had been disclosed to the applicant following his subject access request of March 2010 was not all the material held in respect of the applicant: a considerable amount of further information had not been disclosed on the grounds that disclosure would prejudice the investigation or detection of crime and that the material was thus exempt from disclosure under section 29 of the Data Protection Act (see “Relevant domestic law and practice”, below). 19.  After explaining the nature of his activities and the various units supervised by him, the National Coordinator continued:
“16.  The term ‘domestic extremism’ is not prescribed by law. It is a descriptor generally used by the police service and partners to describe the activity of individuals or groups who carry out criminal acts of direct action to further their protest campaigns, outside the democratic process.” 20.  He then provided examples of how intelligence reports had assisted in policing a Smash EDO protest in 2010 and confirmed that, in his view, the applicant’s data were being processed lawfully and fairly. 21.  A hearing in the judicial review proceedings took place on 9 February 2012. With the agreement of the parties, the Commissioner of Police of the Metropolis was joined as a defendant. The High Court handed down its judgment on 30 May 2012. The court considered that Article 8 was not engaged in the case and that, even if it were, the interference was justified under Article 8 § 2. The applicant was granted permission to appeal by the Court of Appeal on 31 October 2012. 22.  Following a two day hearing during which legal representatives for the applicant, an NGO, the NHRI for England and Wales, ACPO and the Secretary of State presented their arguments, the Court of Appeal unanimously allowed the appeal in a judgment of 14 March 2014. It found that the inclusion of the applicant’s personal data in the database constituted an interference with his Article 8 rights which was not justified. The court said that it did not doubt the importance to modern policing of detailed intelligence gathering and that it accepted the need for caution before overriding the judgment of the police about what information was likely to assist them in their task. It noted that, for present purposes, that task was to obtain a better understanding of how Smash EDO was organised in order to be able to forecast the place and nature of its next protest and to anticipate the number of people likely to attend and the tactics they were likely to adopt. 23.  The court said that it was “not easy to understand how the information currently held on Mr Catt can provide any assistance in relation to any of those matters”. It referred to the comment in the statement of the National Coordinator that it was valuable to have information about the applicant’s attendance at protests because he associated with those who had a propensity to violence and crime. However, it considered that the statement did not explain why that was so, given that the applicant had been attending similar protests for many years without it being suggested that he had indulged in criminal activity or actively encouraged those that did. The court continued:
“44. ... The systematic collection, processing and retention on a searchable database of personal information, even of a relatively routine kind, involves a significant interference with the right to respect for private life. It can be justified by showing that it serves the public interest in a sufficiently important way, but in this case the respondent has not in our view shown that the value of the information is sufficient to justify its continued retention. It is striking that [the National Coordinator] does not say that the information held on Mr Catt over many years has in fact been of any assistance to the police at all. The Divisional Court considered that it was not practically possible to weed out from time to time information held on particular individuals. There is, however, no evidence to support this conclusion and we are not satisfied that it is correct. It should not be overlooked that the burden of proving that the interference with Mr Catt’s article 8 rights is justified rests on the respondent. 45.  That leaves the question whether the interference with Mr Catt’s rights is in accordance with the law. This is very much a live issue given the relatively vague nature of some aspects of the regime contained in the MoPI Code and Guidance and the criticisms voiced by the Divisional Court in C (paragraph [54]) [see “Relevant domestic law and practice”, below] and by the Strasbourg court in M.M. v. the United Kingdom (2012) (Application no. 24029/07). However, in the light of the conclusion to which we have come on the question of proportionality it is unnecessary for us to reach a final decision on the point.” 24.  The Supreme Court granted the Commissioner and ACPO leave to appeal. Following a three day hearing during which legal representatives for the applicant, an NGO, the NHRI for England and Wales, ACPO and the Secretary of State submitted arguments, it upheld the appeal in a judgment of 4 March 2015 by a majority of four justices to one. All five justices agreed that Article 8 was applicable and that retention of the data amounted to an interference with the applicant’s rights under that article. 25.  Lord Sumption delivered the leading opinion for the majority. He set out the applicable legal framework for collection and retention of data. After reviewing the requirements for “lawfulness” under Article 8 of the Convention, by reference to S. and Marper v. the United Kingdom [GC], nos. 30562/04 and 30566/04, § 99, ECHR 2008, he concluded that the interference was in accordance with the law. He noted that the Data Protection Act laid down principles that were germane and directly applicable to police information and contained a framework for their enforcement. These principles were supplemented by a statutory Code of Practice and administrative Guidance (see “Relevant domestic law and practice”, below), compliance with which was mandatory. While, inevitably, there were discretionary elements in the scheme, their ambit was limited. Lord Sumption considered the applicant’s argument that the Code of Practice and the Guidance did not enable him to know precisely what data would be obtained and stored or for how long to be unrealistic. He explained that the infinite variety of situations in which issues of compliance might arise and the inevitable element of judgment involved in assessing them made complete codification impossible. However, he noted, any person who thought that the police held personal information about him could seek access to it under section 7 of the Data Protection Act and, if he objected to its retention or use, could bring the matter before the Information Commissioner. 26.  Lord Sumption then turned to consider the proportionality of the interference. He observed that political protest was a basic right recognised by the common law and protected by Articles 10 and 11 of the Convention. He summarised the facts of the applicant’s case, including the nature of Smash EDO’s activities and the applicant’s attendance at public demonstrations, and the framework for police collection and retention of data in this context. He concluded that the retention of information, including some which related to persons such as the applicant against whom no criminality was alleged, was justified. The starting point, in his view, was the nature and extent of the invasion of privacy involved in the retention of information of this kind, which he described as minor. While the information stored was personal information because it related to individuals, it was in no sense intimate or sensitive information. Rather, it was information about the overt activities in public places of individuals whose main object in attending the events in question was to draw public attention to their support for a cause. Although the collation of the information in the form in which it appeared in police records was not publicly available, the primary facts recorded were and always had been in the public domain; no intrusive procedures had been used to discover and record them. 27.  He then addressed the justification for retaining the personal data for someone who has a clean record and for whom violent criminality must be a very remote prospect indeed. Referring back to the National Coordinator’s statement (see paragraphs 18 to 20), he identified three reasons for the need to retain such data: (1) to enable the police to make a more informed assessment of the risks and threats to public order; (2) to investigate criminal offences where there have been any, and to identify potential witnesses and victims; (3) to study the leadership, organisation, tactics and methods of protest groups which have been persistently associated with violence. He also underlined some basic facts about intelligence-gathering commenting:
“31 ... Most intelligence is necessarily acquired in the first instance indiscriminately. Its value can only be judged in hindsight, as subsequent analysis for particular purposes discloses a relevant pattern ... The most that can be done is to assess whether the value of the material is proportionate to the gravity of the threat to the public ...” 28.  Lord Sumption further considered that the retention in a nominal record or information report of information about third persons such as the applicant did not carry any stigma of suspicion or guilt. It did not imply that all those mentioned as participating in events such as Smash EDO protests were being characterised as extremists. It was further noteworthy that the material was not usable or disclosable for any purpose other than police purposes, except as a result of an access request by the subject under the Data Protection Act. It was not used for political purposes or for any kind of victimisation of dissidents and was not available to potential employers. The material was also periodically reviewed for retention or deletion according to rational and proportionate criteria based on an assessment of danger to the public and value for policing purposes. 29.  In conclusion, Lord Sumption was of the view that sufficient safeguards existed to ensure that personal information was not retained for longer than required for the purpose of maintaining public order and preventing or detecting crime, and that disclosure to third parties was properly restricted. 30.  Lady Hale concurred with Lord Sumption but indicated:
“51. ... it would be more objectionable if the police were to retain a nominal record collecting together all the information that they currently hold about him. Such dossiers require particular justification, not least because of their potentially chilling effect upon the right to engage in peaceful public protest. Mr Catt may be a regular attender at demonstrations, some of which are organised by a group which resorts to extreme tactics, but he himself has not been involved in criminal activity at those or any other demonstrations, nor is he likely to be in the future. Had the police kept a nominal record about him, therefore, I would have been inclined to agree with Lord Toulson that it could not be justified.” 31.  Lord Toulson, dissenting, agreed that the collection and retention of the data by the police was in accordance with the law. However, he considered that retention of the data was disproportionate. He explained that he had no difficulty in accepting in general terms the explanation given in the National Coordinator’s statement, but that there had to be limits, particularly in the case of a person who had never been accused of violence and had been assessed not to be a threat. The statement did not explain why it was thought necessary to maintain for many years after the event information on someone whom the police had concluded, as they had in July 2010, was not known to have acted violently and did not appear to be involved in the coordination of the relevant events. Nor did it explain why it was thought necessary and proportionate to keep details of the applicant’s attendance at other political protest events such as the Labour Party conference and the TUC conference. 32.  He agreed with the Court of Appeal that the Commissioner had not shown that the value of the information relating to the applicant was sufficient to justify its continued retention. As to the suggestion that it would place too great a burden on the police to undertake frequent reviews, Lord Toulson pointed out that there was no evidence from the police that this would be over-burdensome. On the contrary, he said, the thrust of the evidence was that they did carry out regular reviews so there was nothing to indicate that deleting their historic records of the applicant’s attendances at protest events would create any real burden. 33.  Lord Toulson accepted that, when investigating serious organised crime, it was necessary for the police to be able to collate and keep records of the details of their investigations. However, he did not agree that there was any risk of that being hampered by upholding the decision of the Court of Appeal in the applicant’s case. While the court should be slow to disagree with the evaluation of the potential usefulness of evidence by the police if a clear reason for it had been advanced, on the facts of this case Lord Toulson could not see what value they had identified by keeping indefinitely a record of the applicant’s attendances at events where he had done no more than exercise his democratic right of peaceful protest. He concluded:
“69.  One might question why it really matters, if there is no risk of the police making inappropriate disclosure of the information to others. It matters because in modern society the state has very extensive powers of keeping records on its citizens. If a citizen’s activities are lawful, they should be free from the state keeping a record of them unless, and then only for as long as, such a record really needs to be kept in the public interest.”