Back in the mid-2000's, peer to peer lending web sites like Prosper and Lending Club bet that ordinary people could take the place of banks. The business model was both daring and consistent with the hyper-connected internet culture. The idea was that people who needed loans could connect with investors willing to bet on getting paid back with a little interest. Prosper’s faith in crowd-sourcing replacing traditional risk-assessment tools used by banks turned out to be a mistake.