I've never liked these'9-11 truth' campaigners. They seem just a little paranoid, and their methods of portraying their arguments are equally as unnerving as the likes of Fox news who defend the US government.
If you've got the time, Adam Curtis' documentaries are worth a look. The Power of Nightmares or The Trap particularly.
https://www.youtube.com/watch?v=Kggld0A3ssM