A/HRC/31/66 information justifies the intrusion. This should take into account the impact on the rights of all those affected, not only the targets. 78. Practical recommendations: (a) Domestic law should require that the public are notified when they are, or may be, recorded during an assembly. This may, for example, require temporary signage along the planned assembly route indicating fixed cameras, or advisories that unmanned aerial vehicles are filming; (b) States should implement robust and appropriate protections of public privacy and safety prior to the adoption of any biometric technologies, including facial recognition software, in the context of assemblies; (c) States should develop and implement laws and policies requiring that personal information may be collected or retained only for a lawful, legitimate law enforcement purpose. Such information should be destroyed after a reasonable time period set out in law; (d) Relevant information should however be retained where it depicts use of force, detention or arrest, or dispersal, or where it relates to the subject of a complaint; or where law enforcement, oversight authorities or the subject of the information have a reasonable suspicion that a crime or misconduct has been committed; (e) States should put in place mechanisms whereby individuals can ascertain whether and, if so, what information has been stored, and be provided with access to an effective process for making complaints relating to the collection, retention and use of their personal information and that can lead to rectification or expungement; (f) States should put in place clear democratic systems of control for undercover policing — through consistent legislation, regulations and policies — that explicitly incorporate necessity and proportionality tests and that set out clearly how risks of intrusion are to be assessed and managed. This should include an internal review process, as well as oversight by an independent, external body or bodies. Authorization by judicial authority should be required for any undercover policing activity in the context of an assembly. H. Every person has the right to access information related to assemblies 79. The ability to access information is essential to enabling individuals to exercise their rights in the context of assemblies and to ensuring accountability. Information includes records held by a public body at any level or by private bodies performing public functions.53 80. The public should have easy, prompt, effective and practical access to such information, through proactive disclosure and the enactment of legislation to facilitate public access to information. Legislation facilitating such access should be based on the 53 18 See Human Rights Committee, general comment No. 34 (2011) on the freedoms of opinion and expression, para. 18. See also the Declaration of Principles on Freedom of Expression in Africa.