zero tolerance

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A law, policy, or practice that provides for the imposition of severe penalties for a proscribed offense or behavior without making exceptions for extenuating circumstances.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun The strict policy of enforcing all the laws of a state, or the rules of an institution, and allowing no toleration or compromise for first-time offenders or petty violations

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun extreme intolerance of antisocial behavior (usually by an uncompromising application of the law)