I'd bail. Go to a new country, get a new identity, start a new life and just keep in contact with the very few people I trust if my 'darkest secrets' got out and came back to haunt me. Mind you, I wouldn't expect real friends to let that happen, but hey this is a hypothetical here.
I almost went the blackmail option, because I am aware of quite a few potentially damaging secrets from/about friends, but I doubt I'd ever betray their trust (even the stuff they don't know I know about), regardless of if they screwed me over. I have my moral code, and I don't think I'm capable of breaking it, despite bad circumstances.