Yes, there's also:
Zimbardo's prison experiment. Subjects assigned a position of authority took on their assignments with frightening enthusiasm.
Much more mundane, but the peer pressure to give a wrong answer (Asch-Conformity).
http://www.simplypsychology.org/asch-conformity.html
Then we have the real-life example of Abu Ghraib.
http://www.ted.com/talks/philip_zimbardo_on_the_psychology_of_evil?language=en