My cousin showed me Loose Change one weekend when I was home, and he was already sold on the idea.
I had always considered him to be a very rational person for the most part, and although he already believed in a conspiracy by the government to hide knowledge of UFO's (and that they were real), I was still very shocked.
It took about two seconds to realize this video was a joke. I spent several hours listening to him move from one ridiculous claim to the next, with nothing but his doubt to present as evidence. I heard things like, "You don't think they would do something like that?" so many times, and hammered home the fact that, just like his precious UFO's, possibility does not equal probability. He still has a hard time with this. He's backed off the 9/11 thing a great deal, and at one point hinted that he was through with it, but the last time he came over for some beers, some of those same old patterns came out, although with less resistance to my corrections.
But have no fear....now he watches Ghost Hunters like crazy, so I still have a lot of work to do. But since that time, I've gone on to have many debates about 9/11 with different people, and have learned a great deal myself. Like many of you probably have, I've moved on to other subjects, now with a fascination of how and why people believe things like that.
I'm a 'debunker' because people believe insane stuff, and much of these beliefs are dangerous in one way or another. And I'm not immune either....after all, I believed my cousin was rational. Oh, the irony.