Privacy brings security under totalitarian regimes or in countries that shift in that direction. They might say if you have nothing to hide, you have nothing to fear, but there are unjust conditions under which you have to hide things, like that you belong to minority that is targeted by the authorities. Like the nazis did in the third reich, where privacy was reduced during their takeover. Or that you belong to a party that is suddenly framed as evil and enemies of the nation. Or if you have connections to "traitors" or other "scum".

Ask that mother and daughter that got arrested for an abortion after facebook ratted them out.

That's why privacy matters. Not because something bad can happen now, but because that information can be weaponized down the road

I just came across this link on social cooling from another post a few days ago. The amount of information that can be gathered on you is frightening. I just want to be able to control my own data rather than it being taken from me.

Edit: This was also a super interesting read on what privacy actually is as a concept as well as analyzing the social balance of privacy and security.