> Do you understand how widespread this kind of research is? Literally everyone does this.
One of the main objections I'm seeing from people (in my bubble) isn't that Facebook did this, but that Cornell, UCSF, and PNAS participated in this. Facebook can do this, and while it's unethical it's not illegal. Same goes for manipulative people in your everyday life (let me not tell you about the horrific human being of a girlfriend I once had). The point is that science and the people who purport to carry it out should be held to higher and rigorous ethical standards. If those standards are not met, those people should be excluded from science and their findings ignored. They should not be awarded serious consideration in a journal such as PNAS. That is what is happening here as far as I can see, and while a bit dramatic fashion I think it is correct.
Also, if I may toss my personal interpretation of the research into this... ethics aside, the study is extremely weak, and I honestly don't see how it can be published in such a "good" journal. The effect size was < 0.0001. They hand-wavingly try to explain that this is still significant given the sample size. I'm personally not convinced, at all. Sounds like they needed a positive conclusion out of the study and so they came up with a reason for one. If this landed on my desk for review I would have reject on that alone.