Facebook upset the Internet this weekend when a joint study conducted by one of its data scientists revealed that the company had socially engineered the news feeds of 689,003 users to make them feel feelings. For one week in January 2012, those users became unwitting guinea pigs as their feeds were flooded with either positive or depressing status updates from their friends. The goal was to assess whether the mood of their news feeds affected their own mood and behavior, and--surprise!--it totally did. Feelings felt. Critics cried foul. A common thread of argument from academic researchers suggests that Facebook needed the "informed consent" of users in order to conduct psychological experiments on them, with informed being the operative word.