"If you have something that you don’t want anyone to know, maybe you shouldn’t be doing it in the first place. But if you really need that kind of privacy, the reality is that search engines like Google do retain the information for some time, and we are all subject to the Patriot Act, and it is possible that that information may be made available to the authorities." -- Eric Schmidt
Rather than telling users not to worry, he's explicitly warning them that search engines, including Google, are subject to inquiries from law enforcement, and thus, should not be considered secure.
"Privacy protects us from abuses by those in power, even if we're doing nothing wrong at the time of surveillance.
"We do nothing wrong when we make love or go to the bathroom. We are not deliberately hiding anything when we seek out private places for reflection or conversation. We keep private journals, sing in the privacy of the shower, and write letters to secret lovers and then burn them. Privacy is a basic human need."
Snipped from: http://www.schneier.com/essay-114.html