This week, the "study hit the fan" for Facebook, as the world of online media picked up on the controversial Facebook emotion research that we reported early last Saturday and a privacy group filed a formal complaint with the FTC. Meanwhile, Twitter could introduce an integrated "Buy Now" button, Vine added "Loop Counts" and YouTube was found to be more popular than television.

It's time for Social Media Saturday!

Facebook's Creepy Study Followed by Uproar, FTC Complaint

Last week, we devoted most of Social Media Saturday to Facebook's secret emotion study -- which was, at the time, an obscure scientific study that had only been reported by the Onion's A.V. Club and a few others. Boy, did the media pick up on that lead quickly!

The week since, hundreds of news stories and opinion pieces have been written on the study, published in The Proceedings of the National Academy of Sciences, in which researchers with Facebook secretly manipulated the news feeds of over half a million users in 2012 in order to see what effect certain variables had on their shared emotions.

Now, according to The New York Times' Bits Blog, the Electronic Privacy Information Center (or EPIC, a leading U.S. privacy advocacy group) is formally filing a complaint to the Federal Trade Commission over the world's largest social media company treating some of its users like lab rats.

"The complaint concerns Facebook's secretive and non-consensual use of personal information to conduct an ongoing psychological experiment on 700,000 Facebook users," EPIC wrote in its formal complaint, "i.e., the company purposefully messed with people's minds."

EPIC probably has a case since this week's intense media scrutiny revealed that, at the time of the emotion-manipulation study, Facebook didn't seek formal permission from the guinea pig users and indeed hadn't even included "research" in its Data Use Policy. We initially got that part wrong, first reporting the story last week before the news kicked the proverbial Internet beehive. As we later reported, Facebook's policy was only amended to include research purposes after the 2012 study was conducted.

Facebook has responded, according to The Atlantic's Megan Garber, to the controversy by saying that the study was essentially to improve their product, begging the question, "Does Facebook want to tailor our information only to make us happy?" That's a whole new psychological conundrum.

One thing is for sure: Facebook wants to sell ads, which is why it bought LiveRail this week. LiveRail is the third biggest video ad-selling service, which automates the sales of video ads for MLB, ABC Family and Dailymotion, among others. According to the experts at Ad Age, the acquisition puts Facebook closer to Google and AOL when it comes to the world of digital video advertising.

Twitter: 'Buy Now' Button on the Way?

Twitter has been working on upping its advertising and revenue, among other things, after going public on the stock market late last year. Now it appears the struggling public social media company is about to debut a new, possibly very powerful, tool for advertisers: the "Buy Now" button.

Re/code uncovered a mock-up of a tweet with a "Buy Now" button, created by social ecommerce company Fancy back in January. No big deal: Companies experiment with prototypes and UI mock-ups all the time, and the discovery appeared to be just a pitch from Fancy to Twitter.

But this week, Re/code spoke with someone who found a "Buy Now" button that was actually live -- tapping on the button took the anonymous tipster to a checkout page within Twitter's app.

It could just be an anomaly, and Twitter and Fancy are keeping mum on the subject. But the fact that it was reportedly integrated within Twitter's app speaks to the possibility that we might all soon be seeing integrated marketing tweets with a one-step purchase button.

Vine Producers Can Now See Just How Addictive Their Videos Are

Twitter-owned Vine introduced a new metric for creators to see just how popular their six-second videos are. Called the "Loop Count," Vine videos now have a little ticker on the top right of a post that shows how many times the Vine is played, including replays or "loops."

It's similar to the "View" count on YouTube, according to Mashable, and it'll give those Vine celebrities even more of an ego boost, if one of their videos is so good that people don't mind watching it on repeat several times in a row. Of course, if you accidentally leave a Web page with an embedded Vine video open, that Vine will get a lot of "loop counts" from you, even if you only watched it once, so it's not a perfect metric.

The new feature only applies to views of Vines after April 3, when the company began tracking and counting loops, so those "classic" Vines from yesteryear will only display a "+" to indicate that the total view count is probably much higher.

YouTube: More Popular than Television

... According to one survey, at least.

A study from Adroid Digital (via Mashable) has shown that, at least out of the 2,000 U.S. adults who own a TV, smartphone, and computer that it surveyed, video content from YouTube is officially more popular than live TV.

Out of the survey's respondents, 51 percent of people consumed video from live television, while 68 percent said they watched YouTube videos. Netflix was a close third -- quickly on the heels of TV -- with 49 percent of video consumption.

Obviously, the percentages add up to more than 100 because most people are omnivorous media consumers, but the survey is just one more indication of how the digital consumer is shifting much of their media time away from television and toward online streaming.