However, the claim that they made "hundreds of thousands of people fall into a depression" is pretty exaggerated - FB demonstrated it could influence the mood of users via changes to the algorithm, but the overall effect size was small (Cohen's d = 0.001).
I am very critical of FB and this type of research, but don't know if anyone became depressed over the experiment. It's possible, but wasn't demonstrated.
However, the claim that they made "hundreds of thousands of people fall into a depression" is pretty exaggerated - FB demonstrated it could influence the mood of users via changes to the algorithm, but the overall effect size was small (Cohen's d = 0.001).
I am very critical of FB and this type of research, but don't know if anyone became depressed over the experiment. It's possible, but wasn't demonstrated.
[1] http://www.pnas.org/content/111/24/8788.full