Very interesting. Google certainly has some power many people oversee. Put it this way: many people use Google as a universal information source and tend to belive in the results Google returns for the queries. A huge manipulative effect arised if Google just "held back" some information. I'm not implying that Google does this in any form, mind you. But it is possible and practically impossible to prove.

And that is true for a simple search, that is "give me the documents containg these words". As soon as the technology is far enough to offer synthese searches on the scale of todays Google (that is searches like "gather and organize all information about..") Google's power would exponentially grow.

As in many domains, technilogy evolves faster than our understanding of its dangers.