I came across this while reading something in a completely unassociated context:
Godwin's law (also known as Godwin's Rule of Nazi Analogies or Godwin's law of Nazi Analogies) is a humorous observation made by Mike Godwin in 1990 which has become an Internet adage. It states: "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches."
Put another way, Godwin puts forth the sarcastic observation that, given enough time, all discussions —regardless of topic or scope —inevitably wind up being about Hitler and the Nazis.
From Wikipedia (http://en.wikipedia.org/wiki/Godwin%27s_law)
Which made me think of this: