I don’t understand the whole “manipulated the newsfeed” thing. But then I only have one “friend” on my facebook, and that is my son. It’s how we pass stuff back and forth when he is out of state.
Lets just say, you were the sort of person who has 300 Facebook friends, instead of just the one. Facebook chooses who's posts you see unless you choose specifically to force it to show you all of the posts that everyone makes..
Its all or what they suggest. This is the game. Then Facebook tailors what it suggests to you based on their "algorithm." If this is set up to filter out posts that would say things to you that they don't like.. they might cut these out, and the things they are pushing, or being paid to push, these magically show up.
But, this is deeper.. as Google uses a very similar system to prioritize what you see as a search result. Such that they could use your interactions doing simple searches to modify your mood, present a biased view of the facts in a specific situation, etc. This is the bigger issue at stake here..
We know and understand the economics that go with search engine optimization and how this pays for these services.. but they can be used just the same to do things that are not just about raising revenue for operations.