Godwin's Law

Godwin's law (also known as Godwin's Rule of Nazi Analogies or Godwin's Law of Nazi Analogies) is an argument made by Mike Godwin in 1990 that has become an Internet adage. It states: "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches."

In other words, Godwin observed that, given enough time, in any online discussion—regardless of topic or scope—someone inevitably makes a comparison to Hitler and the Nazis.