Some people, DR George, do not know how to read signs, or at least don't bother to read them.
Yesterday, co-worker Chris was telling me of a woman who had piled various kitchen gadgets on the cash-register counter, and kept rapping on top of a sign he had placed there. "Will someone ring me up?" she kept saying, while rapping on the sign. Chris, with a line of customers at the other register, was unable to help her. She finally left in disgust, leaving all her gadgets on the counter (for Chris to put away later).
The sign she had been rapping on the entire time? It read, quite clearly, "Register Closed. Please use other register. Thank-you."