The importance of privacy

I blog some parts of my life. But not all.
In the NSA spying on Americans brugh-ha-ha, some people have stated they don't care if certain benign aspects of their life are known.
My problem is the last century is filled with examples of the State or groups deciding to kill or imprison people because they happened to be  X.  Who cares if your parents came from Haiti and you're living on the Dominican border. Or that your father was an intellectual or shop owner in China? Or when you were 20 you flirted with Communism in America? Or in this same country you're of Japanese decent? Or you're Armenian in the Ottoman Empire? The 20th Century is filled with examples (notice how I'm avoiding the biggest one?) of the State or someone deciding that this or that set of people is the problem or will be a problem, as with the Japanese internments, and going after them.
So yes, now it doesn't matter that the world knows you are or were X. But if the winds change, and blow in a force or a set of know it alls who feel X is bringing the country down or holding the great cause back or endangering the people, is that knowledge so benign?

Also the tools and systems that allow this government to spy on its citizens and others can just as well be used by other nations. I was listening to a podcast of a person who got a FOIA request about the travel information the government had on him. As expected it showed him the flights he took from here to there, but what he didn't expect was there was also information about the hotels where he stayed and local contacts. It also had international travel information. It was supposed that the Chinese had access to this same information by legally demanding an airline, with a presence in China, at their Chinese offices, pull information from this big travel database. And if the Chinese can track people this way, then who else can as well? The Russians, the French (yeah, I know who cares?), the Israelis, and so forth. This endangers activists, which is concerning.