A selection of key paragraph(s) can be found below the document.CASE-OF-CATT-v.-THE-UNITED-KINGDOM
119. However, in the absence of any rules setting a definitive maximum time limit on the retention of such data the applicant was entirely reliant on the diligent application of the highly flexible safeguards in the MOPI to ensure the proportionate retention of his data. Where the state chooses to put in place such a system, the necessity of the effective procedural safeguards becomes decisive (see mutatis mutandis S.M.M. v. the United Kingdom, no. 77450/12, § 84, 22 June 2017). Those safeguards must enable the deletion of any such data, once its continued retention becomes disproportionate.
123. Moreover, the absence of effective safeguards was of particular concern in the present case, as personal data revealing political opinions attracts a heightened level of protection (see paragraph 112 above). Engaging in peaceful protest has specific protection under Article 11 of the Convention, which also contains special protection for trade unions, whose events the applicant attended (see paragraph 10, above). In this connection it notes that in the National Coordinator’s statement, the definition of “domestic extremism” refers to collection of data on groups and individuals who act “outside the democratic process”. Therefore, the police do not appear to have respected their own definition (fluid as it may have been (see paragraph 105)) in retaining data on the applicant’s association with peaceful, political events: such events are a vital part of the democratic process (see Gorzelik and Others v. Poland [GC], no. 44158/98, § 92, ECHR 2004‑I). The Court has already highlighted the danger of an ambiguous approach to the scope of data collection in the present case (see paragraph 97 above). Accordingly, it considers that the decisions to retain the applicant’s personal data did not take into account the heightened level of protection it attracted as data revealing a political opinion, and that in the circumstances its retention must have had a “chilling effect”.
127. Accordingly, the Court is not convinced that deletion of the data would be so burdensome as to render it unreasonable. In general terms the Court would add that it would be entirely contrary to the need to protect private life under Article 8 if the Government could create a database in such a manner that the data in it could not be easily reviewed or edited, and then use this development as a justification to refuse to remove information from that database.