Just to note, while the Stanford experiment was a pretty horrific abuse of scientific power (for which the perpetrator was rewarded with a chair at stanford), its not the reason why all experiments require ethical approval. That honour (?) goes to the Milgram studies on obedience http://en.wikipedia.org/wiki/Milgram_study

Also, that particular anecdote appears not to have a tremendous amount of relevance to the point, but on a completely tangential point, the stanford study was replicated by the BBC ncpsychology.weebly.com/uploads/4/7/8/4/4784501/reicher__haslam_original_study.pdf

The results are extremely interesting, and somewhat counter to the interpretations put forward by Zimbardo.