My concern is that someone out there is accumulating a huge amount of very personal information about me. It happens to be a corporation that has a legal obligation not to me but to its shareholders and that obligation is to maximise profit. It also has a legal obligation to the US government and the US courts, a government I have no right to elect and a legal system I cannot afford.
And here's my point: I simply cannot know or control what profit maximising ideas they may come up with in the future or what kinds of ideas politicians may deem necessary in order to win an election.
Some say that it will always be more profitable for Google to "respect my privacy". The problem is that the meaning of "respect my privacy" is a matter of fast changing attitudes. It's not my personal privacy they need to be concerned about, it's what the vast majority of their users will passively accept.
Their privacy policy says they can do anything with my data to create new services and improve existing ones. That means they can do anything. Full stop.
The reason why I'm more concerned about their new privacy policy than about the old one is that lots of small piles of information are less dangerous than one big pile of information, exactly for the reason they are creating it: The value of accumulated information is more than the sum of its parts.
The conclusions that can be drawn from that combined dataset are a lot more reliable and robust. Right now, much of the data that is out there about us is basically garbage and everyone knows it. No one can know if it means anything that I supposedly visited this or that site. But if they can also analyse what I searched for, what my emails are about, what blogs I read, which people I communicate with, etc, they can learn something about my intentions, not just about my actions and they can throw out the garbage.
I don't want all my intentions to be known or to be knowable to anyone on earth because I cannot know or control the intentions of those wanting to know my intentions. It's a onesided shift of power away from me and I can never take it back.
Once the data has become so much more reliable and the conclusions so much more robust, the desire to use that information for all kinds of new purposes will grow accordingly. The pressure on Google to use that knowledge to increase profit will grow. The incentive for criminals to steal the data will grow. The pressure on governments to proactively spy on everyone to prevent this or that type of crime will grow.
This is not me saying "Google has turned evil". It's just a recognition of an inevitable social and economic dynamic ensuing from the possibilities that well intregrated, high quality, sets of personal data provide.
I know more than the vast majority of people about data analysis and hence I will not delegate what "respecting my privacy" means to that majority of passive Google (or Faceboook, ...) users.