I dread one day having to limit job searches to places that don't make me use my private social networking account to do business.
Maybe not now. But they have it. And correlating it would be trivial.
I'm already annoyed that I get my two factor codes from two different apps (one for Facebook, one for everything else), I'd be extra annoyed if it had to be three.
I feel that the marginal benefit of social media systems has peaked. It's begun to make interactions less human and less personal; the gain over using email is negligible. I don't need to see your picture, I just want to know when I'll have VPN access.
I hope the back lash is enormous. Security = Privacy = Democracy; you can't have one without the others.
Chilling effects brought on by "you should be careful what you say (and to whom)" is the death of freedom of speech, and with it "free" society.