Facebook under fire over ‘manipulative’ secret study

Facebook secretly manipulated the feelings of 700,000 users to understand “emotional contagion” in a study that prompted anger and forced the social network giant on the defensive. For one week in 2012, Facebook tampered with the algorithm used to place posts into users’ news feeds to study how this affected their mood, all without their explicit consent or knowledge. The researchers wanted to see if the number of positive or negative words in messages the...