Back in school, I remember that we were tasked by our history teacher to examine a popular holocaust denial website and compare it to proof. I've always respected him for that, because it was certainly something to learn from. Instead of pretending that such groups doesn't exist, he let us see for ourselves, and see their nonsense fall apart before proof. By putting it in the spotlight, it all became so glaringly ridiculous.
Also, that Rasputin was some sort of powerful sorcerer who consorted with Lenin to grant the Bolsheviks Satan's protection, hence the red star symbol.
Oh, and the idea of a shadowy network of the gay agenda that stretches across the world, possibly consorting with the Old Ones themselves.
Now I think I know why these theories are popular... They're all hell of a lot more interesting than the real deal.