Do you actually think that the terrorist groups would claim responsibility if they knew that they didn't do it? That would be Al-Queda's dream that the U.S. gov't would kill 2500+ of its own citizens. Could you imagine the chaos in our country if that were the case. The terrorists would love it!!! If it were true we would know by now, there would have to be too many people involved and you know that somebody would have come out by now. I mean seriously, use your heads.