Facebook is in hot water, thanks to a psychological experiment the site conducted on 689,003 users without their knowledge.

Facebook is in hot water, thanks to a psychological experiment the site conducted on 689,003 users without their knowledge. The network omitted content from these select user feeds in order to test whether the site can alter the emotional state of its members. The blog post that drew attention to the study expressed the outrage that many have echoed, saying, “Facebook is using us as lab rats [to] actually change our emotions.” (WSJ)