It would be cool if someone created something like prosper, where I could see bad debt from people, and they could make pitches for why I should extinguish theirs. For $x, I could purchase and extinguish N x $x in debt, where N is some function of type, time to maturity, etc.
I personally would be more likely to buy deserving-seeming medical, failed business, etc. debt than car notes or whatever, but maybe others would have their own preferences.