TL;DR: everything is very bad. Prognosis is not comforting; if we do nothing all the distopias we read in fiction novels will look like a happy holiday at your granny's
How they harvest our data
I offer you a new term: dickhead's razor. If it's theoretically possible any instrument will be used for bad. Internet is the best, but we can see live how nuclear power turns into an atom bomb.
I'll tell you, my bagels, how they-who-cannot-be-named harvest our precious data.