At the beginning of July, a big story broke about Facebook conducting behavioral experiments on some of its users without their knowledge, specifically by altering the display order of news feed items to see if looking at lots of good news would make people feel more cheerful, and vice versa. A relatively small subset of 700,000 users was affected, for a fairly brief period of time, and the manipulation was subtle - they were tinkering with how news items were displayed, not hiding them outright - but a great deal of anger boiled over at Facebook for turning users into lab rats. Facebook's clunky P.R. handling of the incident didn't help matters any.
Something similar just happened with OKCupid, a dating web site, which has admitted to deliberately altering information presented to its users so it could learn from their responses. Some have argued OKCupid's manipulation was far worse than what Facebook did, especially during the third experiment described at TechCruch:
In one experiment, OKCupid removed all the photos from its website as it was rolling out a blind dating app to see how it impacted use. In the second, OKCupid ran a test to see how much a user’s picture affects viewer’s perception of their personalities. In the third, OKCupid told users that they had a 90 percent compatibility rate with users who they actually shared a 30 percent rate with.
By removing photos from its website, OKCupid learned information it could apply to its blind dating app. In its second test, it found that users saw personality and looks to be the same thing, and now instead of rating people on both personality and looks, users simply give one overall rating. Its third test seems to be the most controversial, but essentially it confirmed that OKCupid’s dating algorithm actually works — users don’t just work out because OKCupid suggests it.