> Responses like these just legitimize the idea that privacy is about hiding things. It isn't. Privacy is a way of restricting the government's power over you.

I wholeheartedly agree with you. But I'd also point out that most people do in fact have something to hide. So not only is it wrong on principle for the government to invade your privacy - massive surveillance could end up becoming a real, practical problem for many people. Both are important.