For one Facebook owns most of the data. At soe point they tried testing some psychological hypothesis but everyone thought it was unethical. I haven't read this

For one Facebook owns most of the data. At soe point they tried testing some psychological hypothesis but everyone thought it was unethical. I haven't read this article but if you need a pointer https://www.theatlantic.com/technology/archive/2014/06/everything-we-know-about-facebooks-secret-mood-manipulation-experiment/373648/ https://www.theatlantic.com/technology/archive/2014/06/every...