Similar to Murphy's Law, Poe's Law concerns internet debates, particularly regarding religion or politics.
"Without a winking smiley or other blatant display of humor, it is impossible to create a parody of Fundamentalism that SOMEONE won't mistake for the real thing."
In other words, No matter how bizzare, outrageous, or just plain idiotic a parody of a Fundamentalist may seem, there will always be someone who cannot tell that it is a parody, having seen similar REAL ideas from real religious/political Fundamentalists.
The following is an actual Internet post to Biblically defend a flat Earth:
"All I was saying was that either the earth is flat, and the bible is correct, or the earth is round, and the bible is incorect, i'm going to study the issue more and deside for myself which route I want to take. Either Atheist evolutionist, who agrees with all of mainstream sciences, or flat earth litteral bible believer.
I'm leaning toward being an atheist, because if I can't believe the bible to be completly litteraly true, then I can't believe Jesus when he speaks about heaven, etc..
That would make the moon landing a fake, and pretty much all of modern science false..."
"That's it, I'm claiming Poe's Law on this guy."