How to post about Nazis and get away with it - the Godwin's Law FAQ includes some interesting guidelines about refererring to the Nazi's:
"1. If someone brings up Nazis in general conversation when it wasn't necessary or germane without it necessarily being an insult, it's probably about time for the thread to end.
2. If someone brings up Nazis in general conversation when it was vaguely related but is basically being used as an insult, the speaker can be considered to be flaming and not debating.
3. If someone brings up Nazis in any conversation that has been going on too long for one of the parties, it can be used as a fair excuse to end the thread and declare victory for the other side."
Does this mean the conversation was over as soon as Churchill began it?