In one of the first articles that came out in reaction to the study, Sophie Wiener wrote:

Apparently what many of us feared is already a reality: Facebook is using us as lab rats, and not just to figure out which ads we’ll respond to but to actually change our emotions. According to the authors of this study, it was all perfectly legal. Using an algorithm that can recognize negative or positive words, the researchers were able to comb through NewsFeeds without actually viewing any text that may have been protected under users’ privacy settings. “As such, it was consistent with Facebook’s Data Use Policy, to which all users agree prior to creating an account on Facebook, constituting informed consent for this research,” the study’s authors wrote. That’s right: You consented to be randomly selected for this kind of research when you signed up for Facebook. Might want to check out that User Policy again.

A WSJ article about the uproar following the reveal of the experiment discussed the confused intent and execution of the experiment:

On Sunday, the Facebook data scientist who led the study in question, Adam Kramer, said he was having second thoughts about this particular project. “In hindsight, the research benefits of the paper may not have justified all of this anxiety,” he wrote on his Facebook page.

“While we’ve always considered what research we do carefully,” he wrote, Facebook’s internal review process has improved since the 2012 study was conducted. “We have come a long way since then.”

In a recent article on Billboard’s website, the acquisition was further detailed:

Songza employs about 50 music curators, who program playlists designed for moods, activities, times of day, or even weather in the listener’s area – say, “Southern Soul Barbecue” or “Black Tie Bump ‘N Grind.” Google plans to hire all of Songza’s staff, and leave the Songza.com website intact for now.

Google plans to incorporate Songza’s playlists into its Google Play Music All Access subscription service, enhancing its radio function. Google Play already has some human-curated playlists, but largely relies on algorithms for much of its radio-style programming. Songza may also be integrated into a paid YouTube service, which Google acknowledged it is readying.

Songza’s website opens with a picture like this – naming what day of the week it is, what time it is, and then prompting you to choose an atmosphere for which you want music.