check out this paragraph on a listing
"GENUINE BIDDERS ONLY, had numerous time wasters so genuine bidders only please, if you are a zero rated bidder or bidding on numerous items contact me first or I will cancel your bid. NOTE: by bidding you are agreeing to purchase the item, if you don't want it DON'T BID it's really that simple. And don't let your son/gran/dog/dead aunt bid on it either."