OK, if not crazy then just misguided. They already know in their hearts it's a conspiracy so when they work the data it ends up agreeing with what they already knew to be "true". Yes there are government cover-ups and fabrications but it is impossible to do something on this scale without someone talking. Someone involved will have an ego and will write a book or give an interview. It's like the moon landing conspiracy. If it really was faked why haven't they faked it again or faked landing on Mars? On 9/11 almost 3,000 people died. Someone would have a conscience and come forward. I'm not saying the government didn't use 9/11 for their own benefit (PATRIOT ACT, Iraq, etc...) but to say that this was an orchestrated event and no one noticed the preparations is silly. Hell, they may have known it was coming and let it happen but the controlled demolition story is beyond ridiculous. How do you drill holes and plant charges in one of the busiest office complexes in the world while it is operating and have nobody notice anything? Have you seen our government working? They couldn't pull off 9/11 even with the blessing of the American people.
The conspiracy video I have mentions something about a work crew suddenly conducted some emergency repairs of the structure (or something along those lines, it's been a while since I've watched it) a week before the towers were hit. If that's true, it would be an opportune time to conduct such a feat.
I do agree that it would be incredibly difficult to cover it up if it was some sort of inside job just because someone with a conscience would come forward. Then again, who would want to admit taking part in helping to kill 3,000 people? Still, it seems someone would have come forward by now. How many people would have to be involved in a cover-up like this, and none of them have come forward?
That said, the thing that is most suspicious to me is how quickly and perfectly the buildings fell. I can't imagine that all of the beams in the structure were heated up to the same (failure) temperature at the same time. And if they weren't, then the failing beams vs the beams not heated to failure should have caused the buildings to topple sideways, not straight down. Then again, I'm not an engineer by any means, so maybe it's the sort of "straw that broke the camel's back". If one out of 16 beams fail, then the other 15 can't hold the weight or something.
I don't take sides on this. To me, there isn't conclusive evidence one way or another.