Societies rely on privacy to limit the intrusion of others into our lives. It becomes really easy to avoid enforcing a law when you can't see it happening.
For example, without privacy, sodomy laws become much easier to enforce. No longer would it be 2 closeted gay men living together happily, it would be acceptable for the government to setup a mobile array and detect that the two men were sharing a single bed, and then charge them with sodomy.
Another example. In New Zealand, prostitution is legal. However, income information and receipts are private between the business and the tax department. Visiting a prostitute is generally frowned upon publicly. So, what happens when all prostitutes are "outed", and their customer lists published? Is that a good thing? Is it just another way of making the job illegal again, with all of the societal ills that making it legal was intended to avoid?
For a US example, imagine publishing the health records from Planned Parenthood clinics - any and all. Venereal disease, birth control, abortion, anything.
I don't see how we can prevent intrusion of individuals and governments into private areas of life without a definition and expectation of privacy. Particularly when there are differing opinions on morality and what the government should do to enforce it.