You gotta love debates. We all try so hard to change the other side's mind, or to at least prove them wrong. When in fact 90% of people do not want to accept being wrong, let alone admit it to others. So as we voice our opinions with such passion, I think that's important to note.
I will have to comment and say those who believe it's impossible to be an inside job because that many people couldn't keep their mouth shut... I would say very few people knew about it in the first place. It's called our government, and they just so happen to be very notorious for keeping secrets from the public... That's why they're the government. That's why some files remain top-secret for decades upon decades... They are sworn to secrecy and face the imprisonment if they share such intelligence.
So if you don't think it's possible for our government to keep something secret from the general public. Well, then you must have chose the blue pill.