I guess a conspiracy is a theory that challenges either the official or mainstream verdict of an event or incident that happened. To me, a conspiracy theory is usually very much like faith in a religion. Doesn't matter what lack of evidence there is the people who peddle it will still believe in it militantly regardless. That's not to say conspiracies are always false, but they tend to hinge on very little or circumstantial evidence.
It's a shit film starring Mel Gibson lol.
Haha. I actually quite enjoyed that film.