>What happens if you move? Heh. I knew that'd be the first question. Yeah, that's one of the caveats. The auth email or SMS to the previous owner would allow

>What happens if you move? Heh. I knew that'd be the first question. Yeah, that's one of the caveats. The auth email or SMS to the previous owner would allow them to indicate they moved. That would probably handle most cases quickly. But, if no response in x time, it could default to allow and/or if the new owner wants to be proactive, they can send proof of residence. A little bit of a PITA, but doesn't add much to the PITA moving already is. And, moving is pretty infrequent. There's also billing address validation, as that frequently matches shipping address anyway. This kind of validation would also help with other scams.