It can be regulated against, more transparency can be enforced. Despite the enormous lobbying from Facebook and Google in the EU, I could imagine it happening there within five or ten years for example.

There's a real tendency on HN to get all Ayn Rand and forget we live in a society. In relative terms, this is a very new business model. Companies will push for more power, and they get it unless people push back. As people close to the problem, we need to see ourselves as responsible for influencing the discussion about type of society we end up with.