I don't have much of an issue with targeted advertising or content by harvesting of data through what you make publicly available, as long as it is de-identified. It has plenty of applications for good as well. I hope that platforms are working on ways of taking these algorithms to edge nodes, making large master databases containing un-aggregated data that can be used to de-anonymise people less prevalent.

I'm more immediately concerned about blatantly fake news, clickbait, bots, sock-puppets and fake accounts posing as trusted parties in order to harvest trusted information and spread misinformation.