Facebook allowed a research project to experiment on people's emotions by modifying the content displayed on their news feed. Human experimentation in doing things like this is against all ethical principles important in science. If they are willing to commit such a blatant violation of ethics what makes you think they aren't participating in something far worse? I commend Stallman for sharing his opinions on facebook, a modern day societal cancer.
Universities have a lot of "ethical" requirements for experiments, that are, in a large part, over the top. We should get rid of most of those ethical requirements at universities, rather than expand them to Facebook.
