Facebook Experiments Had Few Limits

Facebook's Data Science team is a group of about three dozen researchers with unique access to one of the world's richest data troves: the movements, musings and emotions of Facebook's 1.3 billion users.

Until recently, the Data Science group operated with few boundaries, according to a former member of the team and outside researchers. At a university, researchers likely would have been required to obtain consent from participants in such a study. But Facebook relied on users' agreement to its Terms of Service, which at the time said data could be used to improve Facebook's products. Those terms now say that user data may be used for research. "There's no review process, per se," said Andrew Ledvina, a Facebook data scientist from February 2012 to July 2013. "Anyone on that team could run a test," Ledvina said. "They're always trying to alter peoples' behavior."