Das ganze ist doch schon längst aufgeklärt, siehe Southpark "Mystery of the Urinal Deuce"
http://en.wikipedia.org/wiki/Mystery...e_Urinal_Deuce
Die US-Regierung unterstützt/betreibt die ganzen Verschwörungstheorien aus folgendem Grund:
The point is that, since one-fourth of Americans are "retarded" and will believe conspiracies, the government wants them to believe that it is all-powerful and could get away with the worst terrorist attack in history, while they tell the other 75% of the country the truth—that 9/11 was caused (in Stan's words) by "a bunch of pissed off Muslims."