I see your point, cookiecaper. However there are really three usage cases where I see this potentially becoming a problem: 1. Google sells data to advertisers

I see your point, cookiecaper. However there are really three usage cases where I see this potentially becoming a problem: 1. Google sells data to advertisers directly, without anonymity. 2. Google is rendered insecure and the encryption they use is cracked. 3. Government forces Google to hand over data about individuals or large swaths of individuals. The most likely scenario is number three, which already happens, and this can happen to any information stored anywhere (bank accounts, post office and online). Google would face strong public backlash for selling data to advertisers (#1)directly and would have to change their user policies. Google spends untold amount of money on #2. That's not to say they are completely safe or trustworthy, but it is to say they work very hard at protecting that data (for your and their sake). This situation could just as likely happen to any web provider, linkedin being a recent example. My biggest fear is what happens if the government gets the power to subpoena individuals based on "categorizations" or "keywords". Then I think privacy becomes a serious issue for Google.