"I'd love to be proven wrong. I would love for someone to come to me and say I'm full of sh*t. It hasn't happened," says Avery. "I have scientists on my side. There's so much evidence supporting my side, and the government's side has nothing."
the Loose Change movie is here if you want to see how out how nuts these people are
http://www.rynearson.com/
These "theories" are so insane that there's absolutely no risk of their catching on beyond a small subset of the population that has some organic mental disorder. An awful lot of people saw at least one of the planes hit its target, with their own eyes. And many, many more people have a trusted friend or relative who saw it, and whose account they've heard and believe. Personally, I know a college senior who watched from the window of her high school. She and her schoolmates were already completely focused on the flaming first tower, at the time the second plane approached and hit the second tower. They would have noticed if missile hits had preceded the plane hit, or if the plane was a windowless military jet, rather than the familiar commercial passenger type.
These goofball conspiracy theories are created by people who think that "Occam's Razor" is the brand name of box cutter carried by the terrorists.