How do you know if one is gravely misguided?  I mean, if something this bizzarre had happened in Communist USSR, would we not have been speculating all over the place as to what was really going on behind the official accounts?  Or, by misguided do you mean that it's misguided on its face to think that there are secrets out there that the government can't tell the people about?  Of course there are secrets, and secrets can't be talked about.  If anyone doubts that the government can keep secrets, consider how the stealth bomber was built in total secrecy.  But that's not the kind of secrets I'm talking about.  We all know that the CIA gets involved in some dirty work.  Only recently did Bush reveal the existence of secret prisons.  My point is that on that level, a lot of the secrets would probably shock our conscience and would probably be considered illegal if we only knew what they were.  So, following that logic, is it not conceivable that there is reason to speculate about the truth and still not be guilty of being "misguided?" 

On the other hand, if someone said that 9/11 was caused by an astrological alignment of the planets, then I would say that this person is seriously misguided because subjects like astrology have no relationship to science and can't be proven.