This was covered by all the major news outlets the story died without anything stated in place as far as rulings or laws to ban Facebook from doing this again but they were protected under a private company setting and now being a public traded company can we expect this not to happen again? http://www.pnas.org/content/111/24/8788.full.pdf
"Lack of 'informed consent' means that Facebook experiment on nearly 700,000 news feeds broke rules on tests on human subjects, say scientists"
PNAS Obtaining informed consent and allowing participants to opt out are best practices in most instances under the US Department of Health and Human Services Policy for the Protection of Human
I was looking to see what had been done years later now and dont see anything that has been done.
It was stated that users agree when setting up an account with Facebook that their timeline and newfeed may be manipulated, I believe most users expected this to be used for advertisements being placed and or removal of post that violated terms of service for porn postings etc.