I've now watched the videos, and visited various sites to research this information further, and honestly, I feel sick... really sick, seeing this on the news was enough.
Imagine, if you will... sitting on the 93rd floor of a tower, feeling a gut-crunching shake and realising the building has just been hit, running to the window to see massive explosions, a plane, everyone around you screaming, crying, trying frantically to get out of the building. So after running around a while you then come to terms with the fact that unless you can grow wings, you’re screwed. You then feel the building move a substantial amount, the floor coming from underneath you. You know you're about to die, you know there's nothing you can do, so you just stand there, falling, like the worst rollercoaster you’ve ever ridden, to then get crushed by several hundred tonnes of upper building, your family, your friends, never to be seen again. Just because you went to work, to feed your family, to live. Yeah, that, 1,344 estimated times (and that's just above the 91st floor). Nice.
Anyway, that's besides the topic of this thread. I still stand by my opinion; a minimum of 12 people could have carried this out if this was an inside job, according to reliable sources. 12 is a high amount of people, and 12 of the most powerful minds in the world, I don't think every one of them is corrupt enough to wish that much death for money. Sorry, but I just won't subject myself to that belief, I have far too much willpower and respect for my species to believe that kind of theory, no matter how much evidence you shove my way. There's also a lot of evidence to support the original theory.
In response to MentaL's theories, they're straw-clutching compared to some of the strength in some of the other arguments, but not even those I believe. I think you'll find, with a bit of further research... that most of the debris was left inside the building, and that it's a common error to believe that the plane would leave a lot of large remains, especially at those speeds into a solid object. We're not talking about a car here, and we're not talking about lost.
In conclusion, I've got a great strength of mind, and I refuse to be brainwashed. I believe it's very easy to come up with conspiracy theories for this type of event, but the fact of the matter is... that without replicating an exact copy of this attack, there's no way to prove either way. Everything that's worked out is scientific, and not everything can be worked out via logic and science, you have to accept that things don't always go exactly how science predicts, especially when there are so many other elements involved.