Christopher Allen at Life With Alacrity has a thoughtful post on what he calls the "four kinds of privacy:" defensive privacy, protecting information which puts you at risk from other citizens; human-rights privacy, protecting information which puts you at risk from the authorities; personal privacy, protecting information about your personal life and activities; and contextual privacy, protecting information which can be misconstrued or is inappropriately intimate. I'm not sure the distinctions are as clear as Allen describes, but the essay is well worth reading.
I agree with you that the distinctions are not clear. However, after 4 days of talking to various people with strong interest in privacy at the Computer Freedom & Privacy Conference, I am confident that when someone says "privacy" that one or more of these will be emphasized over others. Understanding the listeners kind of privacy can help you to communicate more effectively and be more persuasive.
For instance, we had a speaker from the US Department of Justice defending the Patriot Act, and John Gilmore of EFF was trying to ask her a question. She was not able to really answer his question because they were speaking about two different things when he asked about privacy and civil liberties. She was more in "defensive privacy" and he was more in "human-right privacy" and thus she failed to understand his question.