October 16, 1989: Godwin's Law is first formulated in a Usenet posting.

Godwin's law (or Godwin's rule), short for Godwin's law of Nazi analogies, is an Internet adage asserting: "As an online discussion grows longer, the probability of a comparison involving Nazis or Hitler approaches one." The law’s creator, Mike Godwin, maintains these comparisons often trivialize the Holocaust. It is an example of the reductio ad Hitlerum fallacy.