I consider fundamentalism more along the lines of this: ""Fundamentalist" describes a movement to return to what is considered the defining or founding principles of the religion."

That's not crazy, unless the defining and founding principles of the religion are crazy. In christianity, perhaps the most defining principle might be that Jesus is Savior. Perhaps the idea of that is crazy to some people, but in and of itself, the notion isn't crazy. Its either true or false, though it would be difficult to falsify (you'd have to find Jesus' remains to prove He didn't rise or something like that).

If you can tell me how the fundamentals of christianity compare to this camp, then maybe I'll believe you, but I think at this point you would have to make the case. This movie might make an argument for a general craziness of some christians themselves, but not of christianity. Besides, things like this aren't necessarily indicative of insanity. Many people in the aryian brotherhood probably have no mental illness. Their group is, however, an unfortunate abberation in otherwise normal social behavior. IE, most people don't lack the self esteem that causes them to fall into groups like these. Or where they lack self esteem, they make up for it in morals.

In this case, camps like these are an abberation in otherwise normal religious behavior.