This is a self-correcting problem: if I buy a Mac from you on Craigslist I’m not going to say “oops, no big deal” if I can’t use it - I’ll ask you to unlink it, reverse a charge, or even take you to small claims court.

Over time, people learn this and it becomes routine just like people buying used cars know to check that the seller really owns it and isn’t lying about the collision history.