If they had been out long enough to be pervasive you could require all online marketplaces ebay,offer up, facebooks etc which are commonly used to traffic stole

If they had been out long enough to be pervasive you could require all online marketplaces ebay,offer up, facebooks etc which are commonly used to traffic stolen goods to upload an NFT as part of the transfer whose description matches the item being sold which is transferred with the good. It would be like requiring every good sold to have a trivially electronically verifiably accurate original receipt that only someone who acquired it illegitimately would lack.