you dont have to be a nutcase to believe there are things that are not be admitted by various people about 9/11. the cia did have known ties with al qaeda and some of the attackers, that much is completely documented, and its not a stretch that some of these people were playing both sides of the fence for whatever reasons.
just because some of the theories and proponents of them are ridiculous doesnt mean all of them are.
Objection, Your Honor. He's reciting the opening to Quantum Leap.