I think you underestimate the extent to which people think their PM's aren't a big deal, until they get released and a torrent of sexting, gossip, illicit relationships, bullying, and public scandal washes over society as fallout.

"I have nothing to hide" is the mantra of fools and people too domesticated to even imagine the ways that malicious crooks and societal pranksters can have it out for them.

I'd consider myself 'tech savvy' and still expect my conversations on Facebook to remain non-public even in the case of security negligence on my part. If anything private is released through this hack, other than hashed passwords or similar (worst case), I'm absolutely done with Facebook and any similar entity.