Poe's law is an adage of internet culture saying that, without a clear indicator of the author's intent, any parodic or sarcastic expression of extreme views can be mistaken by some readers for a sincere expression of those views. The law is also often abused by those who publish sincere extremism, but if there is too much criticism defend themselves by claiming it was only a parody.
Poe's law is based on a comment written by Nathan Poe in 2005 on christianforums.com, an Internet forum on Christianity. The message was posted during a debate on creationism, where a previous poster had remarked to another user: "Good thing you included the winky. Otherwise people might think you are serious".
The reply by Nathan Poe read:
Without a winking smiley or other blatant display of humor, it is utterly impossible to parody a Creationist in such a way that won't mistake for the genuine article.
The original statement of Poe's law referred specifically