I have learned about all sorts of weird and off-the-wall conspiracy theories about a variety of sujects. I have a supers game that flourishes when the characters chase down weird organizations and misfit lunatics. Some of my players' favorites involve bad guys that are conspiracy nuts or centers of conspiracies. For instance, there is a great conspiracy involving JFK which revolves around The Murder of the Devine King, suggesting that some arcane goofballs whacked him as part of a blood ritual. I just adopted that for some villains that were planning something similar.