I wasn't talking about the "law" of getting arrested. If you notice I left it a bit vague. However I am 100% sure the seller will get a lawsuit if the buyer (criminal) cut it open and used it in a crime spree or worst, a shooting. People have been sued for less and lost. I'm just pointing out that the seller has to determine if they want to take that risk. You keep bring up that the buyer is mostly on the hook.
I know that this wouldn't be in your scenario because your a buyer (or maybe it does, I don't know you, but I'm assuming your a law abiding citizen). Please don't take it personally since it's not directed at you. I'm just pointing out there is a major risk for the seller, not a minor one at that.