There was that one time they conducted a study on emotion manipulation on 700,000 people without informed consent. https://www.theguardian.com/technology/2014/

There was that one time they conducted a study on emotion manipulation on 700,000 people without informed consent. https://www.theguardian.com/technology/2014/jun/30/facebook-emotion-study-breached-ethical-guidelines-researchers-say https://www.theguardian.com/technology/2014/jun/30/facebook-...