I've been mulling over the idea of a vouch-based social network. You can follow someone or whatever, and you can also tag them as "person I've met" or "my uncle." If you see a post that's insane or spam, you can open a little graph that shows you that the reason you're seeing this post is because this is your friend's friend's friend, and you can bug your friend about it. Everyone will have a responsibility to only tag people who they know are actual real people who post content with their hands.