I don't think it's productive to categorize tracking of this sort as evil itself. As with any technology, the applications to which it is put are the determining factor of the morality of the tech. In the case of a user knowingly trading their personal information for free applications and some amount of convenience, I don't see evil when that personal information serves the purpose of targeted advertising. When used for targeting web content that might push a person's view more towards the extreme end of the spectrum, we're getting into the gray area quite a bit. Using that information to identify political enemies of the state and preemptively silence them, then yes I'd say that crossed over into the evil side of the spectrum.