Just think for a moment everywhere Google is at the moment. They are have a 70% lead in search, they have 51% of the smartphone market, a near domination of the contextual web advertising and user-submitted video content. Alternatives exist but more often than not there aren't enough competitors or the standard set.
Google really has nothing to rein them in. This is partially because of the hands off approach by some in government towards corporations. It also the consumers fault for not giving the alternatives a chance.