The biggest problem with that theory, is what happens when a missile hits. They show the little hole at the end of one of the rings, and say that a missile could have caused it. Crap! A missile would have penetrated through the first, possibly the second, ring and exploded! You'd have a pattern of damage that looked like a circle around the point of detonation! As much as the conspiracy theorists hate to admit it, the events of 9/11 were carried out by arabian radical islamic-extremists in jet liners. Not by our government, some corporate power, aliens, or the military.