Of course, Caveat Emptor should always be the case when buying anything, and eBay is sending a reminder to all of their buyers (and sellers) of just that. It seems they are having some difficulty with people selling products that have been recalled by the manufacturer. They are threatening to ban sellers who partake in such actions, without any reimbursement.
In this case, I agree with eBay. While you might expect a used item to not last as long or have some wear, with a recalled item you might be staring at something that appears to be brand new but then combusts and sets your house on fire (like a bad laptop battery).
Even eBay, however, admits that they cannot watch every auction – and as such they are providing “tip sheets” and links to recall databases to see if something you might be buying is tainted.