I really don't think Facebook changed my point of view on the human race as a whole but instead changed how I thought about certain individuals. When you have over 500 friends you tend to forget who is really looking at your status updates. For a brief moment, you think you're safe to say something negative about a person you might not like. You think it'd be ok just to vent a tiny bit, insult this person once or twice and then... he or she comments on your status update and fights break out. You use these silly little updates against each other in the future and suddenly start seeing only the bad. Thats how it was like for me, anyways.
I honestly don't know what about Facebook makes nearly everyone post ridiculous things about each other but it's definitely ruined a handful of friendships for me. I'm assuming it has for others as well. Somebody out there somewhere probably hurt that "slitty little prep" they forgot was on their friends list. You know, I really don't understand adding people you know you don't talk to and probably won't ever talk to on Facebook. I bet if you went and cleaned your friends list right now, you'd have nearly nothing compared to the number of friends you had just a moment ago.