I would love if someone made a Chrome extension that encrypted all the posts and messages you put on Facebook. That is, any post you made would be made as a ciphertext, the extension would swap keys with all your friends in the background, and would decrypt their posts when displaying them to you.

Sure Marky Mark still sees when you post, who you send messages to, etc. but it's a much better situation than what's going on now. Plus it would probably put a dent in their bottom line, and so send them the message that privacy matters to people.