Quiet, Peace and

Librarians can avoid confrontations with unruly patrons by offering courtesy earplugs to people who complain about noise. If your library can’t afford to supply all patrons with earplugs, just buy enough for the library staff. Then you won’t hear anyone complaining about the anarchy taking place in your building.

Quiet, Enforcing

Set up a "quiet zone" in your library for your militant, overly-confrontational, hostility-seeking librarian to patrol.  This librarian-warrior should be provided with camouflaged clothing, a tazer (equipped with a silencer), and an intimidating metal finger guard for extreme shushing.

Shushing, Equal opportunity

It is your responsibility as a librarian to inform library patrons when their headphones are too loud. Nevermind if the patron has impaired hearing and turns out to be using an assisted listening device. Disabilities are no excuse for noisiness in the library.