A selection of key paragraphs can be found below the judgment.
37. The Court observes that the police dispersed the assembly of seven people and a fine was imposed on the applicant following the administrative-offence proceedings on the sole grounds that no prior notification of a static demonstration had been given to the authorities. (…)
41. Under the Court’s well‑established case-law, an unlawful situation, such as the staging of a demonstration without prior authorisation, does not necessarily justify an interference with a person’s right to freedom of assembly. While rules governing public assemblies, such as the system of prior notification, are essential for the smooth conduct of public demonstrations, since they allow the authorities to minimise the disruption to traffic and take other safety measures, their enforcement cannot become an end in itself. In particular, where demonstrators do not engage in acts of violence it is important for the public authorities to show a certain degree of tolerance towards peaceful gatherings if the freedom of assembly guaranteed by Article 11 of the Convention is not to be deprived of all substance (ibid., § 150)
44. The Court further points out that it has previously held that the offence set out in Article 20.2 § 2 of the CAO should be classified as “criminal”, regard being had to the general nature of the offence, and given that the purpose of the sanction is punitive and deterrent in nature, all of which is a characteristic of the criminal sphere (see Mikhaylova v. Russia, no. 46998/08, §§ 57-69, 19 November 2015, and Navalnyy, cited above, § 79). Accordingly, the applicant was subject to sanctions which, although classified as administrative under domestic law, were “criminal” within the autonomous meaning of Article 6 § 1, thereby attracting the application of this provision under its “criminal” head. However, a peaceful demonstration should not, in principle, be rendered subject to the threat of a criminal sanction and notably to deprivation of liberty. Where the sanctions imposed on a demonstrator are criminal in nature, they require particular justification. The freedom to take part in a peaceful assembly is of such importance that a person cannot be subject to a sanction – even one at the lower end of the scale – for participation in a demonstration which has not been prohibited, so long as that person does not her or himself commit any reprehensible act on such an occasion (see Navalnyy, cited above, § 145)
45. In view of the above, the Court cannot find that the applicant’s freedom of peaceful assembly as protected by the Convention was outweighed by any interests on the part of the respondent State in restricting the exercise of that freedom with a view to preventing disorder. The reasons relied on by the respondent State did not correspond to a pressing social need. Even assuming that they were relevant, they are not sufficient to show that the interference complained of was “necessary in a democratic society” (ibid., § 146). Notwithstanding the national authorities’ margin of appreciation, the Court considers that there was no reasonable relationship of proportionality between the restrictions placed on he applicant’s right to freedom of assembly and any legitimate aim pursued.