The ALA seems pretty clear that restricting access to library materials violates the ALA's Library Bill of Rights.
Though they do acknowledge that libraries sometimes restrict access to prevent theft or damage, or because of regulatory requirements.
If restrictions (or lack thereof) are due to regulations of the library system or school district, the librarians are probably not the ones who should be blamed.
99% of the neck beards that want to ban books in libraries don't have the slightest idea how a library runs, about library boards and how they're related to their local governments.
So when they see a book that offends their easily offended sensibility they're gonna go right to the people they see standing around in the building.
