On a number of occasions recently, I've been bidding, or considering a bid, on ebay and have looked at the lists of other bids. Several times, the "top bidder" was a hidden name with 0 feedback who had apparently made dozens of bids in a relevant area within the last minute.
On one item, I was the next to top bidder both on the original outing and on the time it was relisted. On both occasions, the item had a top bidder with zero feedback and something like a dozen bids in different categories within the minute. The item was subsequently relisted a third time with a buy it now price. Another auction that I just watched had a similar strange bid supposedly "winning" it.
I've also sold a couple of things recently where the "winning bidder" didn't pay but had 100% positive feedback. When I read the feedback, even though it was positive, the comments were things like "Avoid, doesn't pay".
I assume it's children at play rather than fraud, but has anyone any better theories?