In Catt v ACPO and others; T v Commissioner of Police of the Metropolis and another  EWCA Civ 192, the Court of Appeal considered two appeals regarding the powers of the police to collect and retain personal information about members of the public. Both cases turned on the application of Article 8 of the Convention; in both, the Court held that there had been an interference with the Article 8(1) right to respect for private life, and that the interference was not justified under Article 8(2).
The retention of personal information by the police has given rise to extensive litigation in recent years: see e.g. Chief Constable of Humberside and others v Information Commissioner  EWCA Civ 1079 (retention of conviction information on police national computer); and S and Marper v UK  ECHR 1581 (operation of national DNA dabatase). Although the Humberside case concerned the Data Protection Act 1998, since it arose out of enforcement action taken by the Information Commissioner under that Act, most of the cases have turned on the application of Article 8. A recurring issue, and one on which the Catt case is especially important, is whether and in what circumstances the recording and retention of information about events taking place in public will constitute an interference with the Article 8 right to respect for private life.
The first appeal concerned Mr. John Catt, described in the judgment of the Court as someone who “over a long lifetime has been an ardent and frequent protestor against what he sees as a variety of forms of injustice”. He had attended public demonstrations organised by “Smash EDO”, a group campaigning against a weapons manufacturer operating on the outskirts of Brighton. Some of the core supporters of Smash EDO were prone to violence and criminal behaviour, but Mr. Catt had not been convicted of criminal conduct of any kind in connection with any demonstration that he had attended. Personal information about Mr. Catt was held on the National Domestic Extremism Database, mostly consisting of reports by police officers attending Smash EDO demonstrations. Mr. Catt had not been the specific target of observations, but was referred to incidentally in descriptions of what the police at the scene had observed. It appeared that this information was to be retained indefinitely.
In judicial review proceedings, Mr. Catt contended that the continued retention of this information about him constituted an unjustified interference with his Article 8 rights. His claim was rejected by the Divisional Court.
The second appellant, referred to as Ms T, was served with a police warning letter following an allegation that she had directed a single homophobic insult against the friend of a neighbour. She denied the allegation; in judicial review proceedings based on an alleged infringement of her Article 8 rights, she sought an order that the police should destroy their copy of the warning letter and remove from their records all references to the decision to serve it. Again, her claim failed at first instance. Before the appeal hearing the police reviewed the information and decided to expunge it, but the Court of Appeal nevertheless heard and determined the appeal because of the importance of the issues raised.
The judgment in Catt begins with a survey of recent developments in relation to Article 8. This part of the judgment is likely to become an important reference point in any future cases about the retention and use of police information.
As to the circumstances in which there would be an interference with the Article 8(1) right, the Court began by referring to the observation of Lord Nicholls in Campbell v MGN Ltd  UKHL 22, that the touchstone of private life is whether in respect of the disclosed facts the person in question had a reasonable expectation of privacy. However, recent cases showed that the position was more complex. Even information of a public nature could become private over the course of time, as memories faded. Moreover, the storage and use of personal information gathered from open sources could nevertheless involve an interference with private life.
In relation to justification under Article 8(2), the Court reiterated the three well-known requirements that the conduct in question must be in accordance with the law; carried out in pursuit of a legitimate aim; and proportionate to the aim sought to be achieved. The issue of “legitimate aim” did not cause any difficulty in the present cases: the police were acting to prevent disorder and crime, and protect the rights and freedoms of others. In cases about the collection and retention of personal information about private individuals, the issues of legality and proportionality were closely related. As to proportionality, the overriding principle was that there should be a fair balance between the personal interest of the claimant in maintaining respect for his public life, and the pursuit of a legitimate aim in the interests of the public at large. The Court needed to pay careful attention to the nature of the information in question, the circumstances in which it could be obtained, the ways in which it could be processed and by whom, the period of retention, and the arrangements for its destruction.
Applying these principles to Mr. Catt’s case, the first issue was whether there was any interference with his right under Article 8(1). The Divisional Court had held that there was not: none of those attending the Smash EDO demonstrations can have had a reasonable expectation of privacy, since it was of the essence of such activity that it was of a public nature. The Court of Appeal took a different approach, focusing on the collection and retention of data about Mr. Catt rather than on the public nature of his activities at the demonstrations themselves. The processing and retention of even publicly available information could constitute a interference with Article 8 rights, especially when the information was subjected to systematic processing and entered on a database that was searchable by reference to specific individuals.
Turning to the issue of justification under Article 8(2), the Court focused on the issue of proportionality. It accepted that the police needed to obtain a better understanding of how Smash EDO was organised, so as to anticipate its future conduct and tactics. However, the Court did not consider that the information held about Mr. Catt was of sufficient value to justify its retention. It commented that the police appeared to be recording the names of any persons they could identify at Smash EDO demonstrations, regardless of the nature of their participation. The retention of Mr. Catt’s information on the database was therefore an unjustified interference with his Article 8 rights, and hence was unlawful.
As to the second case, that of Ms T, the Court held that the action of the police in issuing the warning letter did not in itself amount to an interference with her Article 8(1) rights, but that the retention in police records of a copy of the letter, and information describing the circumstances in which it had been issued, did constitute an interference. While the retention of this information for a short period was justified, it was hard to see how retention for more than a year or so could be of any value. If the information had not been destroyed before the appeal hearing, then its continued retention woud have been disproportionate.
The message from both cases is that, even where events take place in public, the recording and retention of information about them can interfere with the right to respect for private life. The Court is especially concerned with the sitation where information is retained indefinitely on databases where it is searchable by reference to individual names. In relation to justification, the cases suggest that the Court will scrutinise closely both the precise nature of the information retained, and its value for policing purposes. The analysis in Catt will be an essential starting-point in any future consideration of how Article 8 applies to police use of information.