An
extreme reaction to
bad events. A
policy that no
deviation from the
rule, no matter how
small, or whatever its
intention, will be
accepted. Often
includes going after just the
appearance of
violating the policy, and sometimes even going after the appearance of having the appearance of violating the policy.
After some incidents of school shootings, zero tolerance has been the rule at some schools, who have done such wonderful things as suspending a girl for months because she had fingernail clippers that supposedly had a small knife in them. Or suspending a boy for four months because he convinced a suicidal girl to give him the knife and he put it inside his locker.
Zero tolerance is in effect the sacrifice of a few for the good of the others.