I've never had a "meter" with which to measure my faith in humanity: it stays fixed. I know that human beings are grey in morality. Some slate grey, some plainsboro grey. Capable of great good, great evil.
However, human beings are actually greatly limited in their capability to commit atrocity. For example, the laws of physics do not allow for, say, a human being to soar to the sun and push it into the earth, as Rich points out in this essay,
http://www.godandscience.org/apologetic ... _will.html
I think if you have a faith in humans, it's just going to be shook. That's why I don't have one, I have an understanding that we are perfectly imperfect beings, and that's the best way things could have turned out.
edit: Ah I just realized this was posted in humor and jokes....but I'm gonna keep this up because I like it