The FTC confirmed receipt of Warner's letter but declined further comment.
The Facebook researcher behind the experiment has defended it, and said the research aimed to investigate a common concern that seeing friends post positive content leads others to feel negative or left out.( The three researchers were also concerned that exposure to friends' negativity might lead people to avoid visiting Facebook.
The Facebook algorithm reduced exposure to friends' positive emotional content in the news feed in one experiment, while reducing exposure to negative emotional content in the feed in a parallel experiment. In the paper, the authors held that the experiment procedure "was consistent with Facebook's Data Use Policy, to which all users agree prior to creating an account on Facebook, constituting informed consent for this research."
Sign up for CIO Asia eNewsletters.