Information is power. Telecommunication have changed the landscape of business, warfare, and how we live. It allows us to make “better” decisions for what we set out to do. Whoever holds more information, and has the chops to analyze it, controls the board. The closer that information is to individual people, the sharper it is as a weapon.

Having power too concentrated in one place or a few has led to disastrous consequences in human history. Privacy is simply a way to hold that power back, so that the most sensitive information are kept away from unknown hands.

Privacy also allows us to be ourselves, in the sense that we have different fronts of ourselves. We have sides we don’t necessarily want to show to our parents, but we show it to our friends or spouse. Not everyone has the best of relationships with everyone around them, and so there are sides we don’t want everyone to know, lest they get used as a weapon against us, either for others to exploit, or hold us ransom. If you’d like an example, imagine having an overly possessive religious parent, and you’re an atheist, but you don’t want to confront your parent because you’d like to avoid trouble. When thought in that way, privacy is a right that humans should have, and it is each person’s right to release what information they have about themselves to whoever they wish.

I have a mental illness that, while protected under the law, is heavily discriminated against. It's nice to be able to talk about my disability without my employer finding out.

Oh, the contempt with which people speak about their loved ones on the internet? Privacy allows that. It's really fun to watch (and provoke). I'd lose a source of entertainment.