Here's a quote in the crowdfunding article by Berkeley Geddes, head of a professional association:
"The crowd has a powerful ability and can say, ‘I know this person’s past and I can vouch for him, or I know his past and I have some concerns,’ Geddes said. "The crowd has a unique ability to help make sure that the entrepreneurs asking for the money" are legitimate.
I presume there were people vouching for alleged Ponzi schemers, too. Potential crowdfunders should probably worry about the incentives of the people doing the vouching, which raises the question of who's going to vouch for the people doing the vouching. And then who's going to vouch for the people vouching for the people doing the vouching. And so on.