"I’m thinking of friends who get upset at learning the government is spying on everyone, who simultaneously post countless intimate details of their lives on Facebook (or Instagram, Twitter, Reddit, etc.)"

This is not a contradiction. When you post, you can choose, what informations get out. You have control. (in theory)

When you get spied on, you can't choose. In other words, yes the whole world may see pictures of me and my friends (even though I don't post on those services), but I still don't share my bedroom insights nor pillow talk.