The people who talked about "social" lending clearly hadn't talked to the lawyers.
If they had, they'd have realized that lenders couldn't be allowed to communicate with borrowers because they'd almost certainly run afoul of the debt collection laws the minute they did. And because lenders aren't allowed to communicate with borrowers, the "social" aspect is diminished to irrelevance. The idea that people will feel more obligation to repay anonymous "ordinary folks" they borrowed money from over the internet then will to repay banks and other institutitons that have regular collections doesn't seem to bare out.
Lending Club used to present the idea that social lending was less risky than regular lending. They've long since removed any mention of the idea.