Wrecking Yard/Recyler "Ink Pen"?

Pick-a-part: I always tell them dont mark it, Im not going to return it. One guy insisted on marking it up (TQ carb, top and body!) and since I had already been checked out (its done at the security exit, I just walked away with it. The guy was quite disturbed at this action and started a machine gun stacatto of Spanglish directed towards me and the other workers...OK bro, means nothing to me if I cannot understand it. They will mark your + lug wrench if you bring it in too.