The legality of banning a citizen from a public library can vary depending on the policies and regulations in place in a particular jurisdiction. Public libraries are typically funded by taxpayers and are intended to provide access to information and resources for the community. However, libraries also have rules and codes of conduct that patrons must follow to ensure a safe and respectful environment for all users.
If a patron violates these rules, such as engaging in disruptive behavior, damaging property, or engaging in illegal activities, the library may have the authority to restrict or ban that individual from using library services for a certain period of time. The specifics of how bans are implemented and enforced can differ between libraries and jurisdictions.
It's important to note that any restrictions or bans should be carried out in accordance with applicable laws and regulations, as well as the principles of due process and fairness. If you have a specific situation or concern regarding a library ban, it's best to consult the library administration or seek legal advice to understand the specific rules and procedures in place in that particular library and jurisdiction.