Does it matter? If they don't pay, there are plenty of fall back bids.
Its a problem. Think about it. Price at 60BTC. The bidder that wants to win bids 10@61BTC. Then he goes in with a fake account and bids 10@210. He knows that he wont pay the higher bid so that he will get all miners for 61BTC. Effectively forcing out all other bidders because they cant bid anymore. Theres no protection yet except reputation or something. But i think many users here on the forum have many different forum accounts. And are they only created for getting the ripple giveaway.
I think requiring a deposit from unknown members(to John) to show that they mean business is a good idea.