Actually eBay fed you a crock of poo. Their software most certainly is able to flag and require additional authentication for "pre-approved bidders only" auctions separately from regular auctions. It would take about one person part time to police this with their software. They simply have chosen to not bother; fact per an eBay representative. It is obviously going to take someone to sue eBay for tens of millions of dollars for eBay knowingly allowing a form of auction to be used that is almost all attempts at fraud to continue without eBay doing anything to protect the public. And, I'll give you pretty good odds that eBay will lose such a suit with the tens of thousands of people who have complained about the blatant fraud attempts on almost every single "pre-approved bidder only" auctions. On this issue, eBay is simply being flat stupid; no other way to describe their lack of action to protect the public from fraud.