Lots of users = leverage = power. All power corrupts. At least this particular corruption happened out in the open. I suppose decentralized browsers is the answer in theory.
Pardon me, decentralized search engines, not browsers. Either way, some attempts have been made, but it is a difficult thing to decentralize properly it seems.
Lots of such stuff is surely happening, it seems like NSA thinks that this is their job. As for DDG, they say they do not spy and so on, but obviously NSA still get their data.