Distrust users
  Users are
  Extreemly error-prone.
  Inherantly stupid.
  Often malicious.
  You should never trust user input.
  Verify everything you are given before acting on it.
  Verify the data is entirely good, rather than determining some of it is bad.
  If you overlook something, you'll deny something that was ok, not allow something harmful.

Copyright 2003, Bri Hatch of Onsight, Inc.

Presented at SPUG, 2003.

Presentation created using vim and MagicPoint.