The full judgment by the Master of the Rolls, Lord Dyson, along with Lord Justices Moore-Bick and McCombe, is now availble at the British & Irish Legal Information Institute, BAILII, and makes interesting reading.
The good Lords quote repeatedly from the European Court of Human Rights decision, S & Marper v UK, where the Court held that the systematic blanket indefinite retention, by the police, of the DNA and fingerprints of people not charged with or convicted of a crime, was in breach of of Article 8 of the European Convention on Human Rights, relating to respect for privacy. They also rely on R (Wood) v Commissioner of Police of the Metropolis  EWCA Civ 414 where an employee of an association campaigning against the arms trade was followed and photographed by police and "the element of surprise and the claimant's uncertainty about the purposes of the police in taking his photograph and the use to which it might be put meant that article 8 was engaged."
They essentially conclude that the treatment of Mr Catt is disproportionate and constitutes an unjustified interference with his article 8 right to respect for private and family life.
From my reading of it, which I hope has been more careful than the erroneous quote I attributed to the Court yesterday evening on Twitter (thanks, btw, to the several folks who alerted me to that), the key elements of the decision relating to Mr Catt are in paragraphs 23, 24 and 41 through to 46, the core of the judgment coming in paragraph 44 (I've emphasised this in bold print in para 44 below).
- However, it was also recognised in S, that in cases which concern the collection and retention of personal information relating to private individuals the issue of legality turns to a large extent on the circumstances and manner in which that information is collected, processed, stored and ultimately destroyed. Questions of that kind are closely related to the broader issue of whether the interference with the right to respect for private life is necessary in a democratic society (see paragraph ). In S itself the court found it unnecessary to consider the question of legality having held that the retention of the information was disproportionate to the aim sought to be achieved and in those circumstances we turn to the question of proportionality.
- [...] The overriding principle is the need to strike a fair balance between the personal interest of the claimant in maintaining respect for his private life and the pursuit of a legitimate aim in the interests of the public at large: see, for example, S, paragraph . In order to justify the collection, processing and retention of personal information the state must be able to satisfy the court that each of those steps is governed by clear rules of law or policy which are both accessible and intelligible and do not give the authorities an excessively broad discretion over the manner of their implementation. In such cases it is therefore necessary for the court to pay careful attention to the nature of the information in question, the circumstances under which it can be obtained, the ways in which it can be processed and by whom, the period for which it can be retained (together with any arrangements for interim review) and the arrangements for its destruction.
- Having seen copies of various reports in which Mr.Catt is mentioned and the information provided in response to his subject access request, we are left with the clear impression that police officers who attend protests organised by Smash EDO for the purpose of gathering intelligence record the names of any persons whom they can identify, regardless of the particular nature of their participation.
- The Divisional Court held that the continued retention on the Database of information relating to Mr. Catt was in accordance with the law and proportionate to the aim sought to be achieved. As to the latter, the court held that any interference with Mr. Catt 's rights was minimal [...] The court regarded as "wholly unworkable" the suggestion that the respondent should be required to trawl through reports in order to consider each person named in them in isolation with a view to weeding out information no longer of value.
- Proportionality involves striking a fair balance between the rights of the individual and the interests of the wider community. In paragraph  of his judgment in Wood Dyson L.J. drew attention to the fact that in striking that balance the court must have regard to the nature of the Convention right in issue, its importance for the individual, the nature of the interference and the object pursued by the interference.
For those ill-inclined to read the full judgment in detail, note that the Mr Tudway referred to in para 44 is Detective Chief Superintendent Tudway, a serving officer with the Met and a previous incumbent of the post of National Co-ordinator for Domestic Extremism ("NCDE") - effectively the guy who was in charge of the National Public Order Intelligence Unit and, therefore, the 'National Extremism Database'.
- We do not doubt the importance to modern policing of detailed intelligence gathering and we accept the need for caution before overriding the judgment of the police themselves about what information is likely to assist them in their task. For present purposes that task is to obtain a better understanding of how Smash EDO is organised, to be in a position to forecast the place and nature of its next protest and to anticipate the number of people likely to attend and the tactics they are likely to adopt. It is not easy to understand how the information currently held on Mr. Catt can provide any assistance in relation to any of those matters. Mr. Tudway states in general terms that it is valuable to have information about Mr. Catt 's attendance at protests because he associates with those who have a propensity to violence and crime, but he does not explain why that is so, given that Mr. Catt has been attending similar protests for many years without its being suggested that he indulges in criminal activity or actively encourages those that do. 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 Mr. Tudway 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.
- 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 [...] 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.
- For these reasons we have reached the conclusion that the interference with Mr. Catt 's right to respect for his private life has not been justified and that the appeal must therefore be allowed.
It's impossible to over-emphasise the key section of paragraph 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. [...] 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.Impossible to over-emphasise because this is where we are losing the privacy wars - to the public and private sector armies of determined, hardworking, occasionally efficient, often well-meaning, silo-mentality, target driven, sometimes sociopathic/psychotic and ambitious bureaucrats who are just doing their jobs in their routine systematic, purpose-fuzzy collection, processing and retention on searchable databases of personal information. Their default assumption is that such activity serves the public and/or their organisational/personal interest in a sufficiently important way.
Society's passive acceptance of the consequent emergent normalisation of organisational sociopathy constitutes a clear and present danger to the right to respect for private and family life. As Justice Brandeis put it much more eloquently in his dissent in the 1928 US Supreme Court wiretapping case, Olmstead v. United States:
"Experience should teach us to be most on our guard to protect liberty when the Government's purposes are beneficent. Men born to freedom are naturally alert to repel invasion of their liberty by evil-minded rulers. The greatest dangers to liberty lurk in insidious encroachment by men of zeal, well meaning but without understanding."And those persons of zeal lurk not just in government but also out there in the real world.