Godwin's Law

[Dave Monroe]

Godwin's Law FAQ
-or-
"How to post about Nazis and get away with it"

One of the most famous pieces of Usenet trivia out there is "if you
mention Hitler or Nazis in a post, you've automatically ended whatever
discussion you were taking part in".  Known as Godwin's Law, this rule
of Usenet has a long and sordid history on the network - and is
absolutely wrong.  This FAQ is an attempt to set straight as much of
the history and meaning of Godwin's Law as possible, and hopefully
encourage users to invoke it a bit more sparingly...

http://www.faqs.org/faqs/usenet/legends/godwin/