Step-by-step procedures will make it easier for library workers and volunteers to adhere to your policy when someone asks for information about library users. Keep these procedures up-to-date and readily available at each service point.
ALA guidance for responding to inquiries from law enforcement: https://www.ala.org/advocacy/privacy/lawenforcement
ALA information on "First Amendment auditors" who film in the library: https://www.oif.ala.org/auditing-the-first-amendment-at-your-public-library/