Facebook Tinkers With Users’ Emotions in News Feed Experiment, Stirring Outcry

Facebook revealed that it had manipulated the news feeds of over half a million randomly selected users to change the number of positive and negative posts they saw. It was part of a psychological study to examine how emotions can be spread on social media.

The company says users consent to this kind of manipulation when they agree to its terms of service. But in the quick judgment of the Internet, that argument was not universally accepted. The Facebook researcher who led the study, Adam D. I. Kramer, posted a public apology on his Facebook page. “I can understand why some people have concerns about it, and my co-authors and I are very sorry for the way the paper described the research and any anxiety it caused,” he wrote.