I've always thought that if I got my master's degree that I would write my essay or thesis on group mentality. That's just one of the interests I have. Now in this movie, it wasn't necessarily a group but there is still that sense of going along with something, then another person goes along with it and so on.
I can't judge the people in the movie (it is based on actual events) but it's kind of hard not to. I've tried to think back about times that maybe I did something stupid because someone told me to but the only real instance I can remember was in high school. That time I jumped off of a bridge because my friends were even though I could not swim. I trusted them to help me across the water and they did but looking back, how unbelievably stupid was that? If anything, this movie certainly begs to ask the question of how much should you listen when someone is telling you something that doesn't sound right?