So I purchased a used Mac Mini, used it for a few months, and sold it to somebody else on ebay. I had formatted and re-installed OSX prior to shipping it out. Now the buyer is nagging me about unlinking the serial number from the "support profile," and I can't since it is linked to somebody else other than myself. He states that since it is still registered to someone else, that they can still go in and remotely wipe the system. Is that true? If so, what can I do as I do not have contact for the person I purchased it from. Thanks!