Actually, now that I think about it, that might screw up customer support... so how about this. A merchant can find out if someone is on the buyers' list, but only by looking for that particular name. i.e. If a person asks for help with a product, and the merchant wants proof of purchase, they can go to their accounting page and enter the name, and receive a simple confirmation or denial notice. A bad merchant could still go after people, but the effort required might dissuade them.