Google the new big brother ?

Force for good, or force for evil? It seems to be everywhere now, introducing new tools everyday. Big brother or Benefactor friend ? On one hand they are so genial, and on other and they scared me.
First you must see this videos : part 1, 2, 3.
Curently, google make a lot of attractive tools, and moreover free tools ! (google docs, Google earth,…) but with this tools they can watch what you do 
This problem is about the question of privacy, because google use your personal information to impose ads on your computer. They know who you are, what you buy, what are your search on the web, where you live, but it is a problem ?
If google use this personel information to just do targeted advertising is not a problem and maybe a good thing. In this way you can buy some product you like.
But if google sell this personal information to other firm is a problem, because you lose the control of your private life. and privacy is “the ability of an individual or group to control the flow of information about themselves and thereby reveal themselves selectively”