excellent piece on feedback loops between recommendation engines and procedurally-generated content, specifically with regard to videos targeted to children on youtube: https://medium.com/@jamesbridle/something-is-wrong-on-the-internet-c39c471271d2 (content warnings in article)
reminds me of cathy o'neil's concept of "weapons of math destruction" in which data-driven algorithms feed back on data from the society that they create http://time.com/4471451/cathy-oneil-math-destruction/