LONDON The verdict on Banksy 's artwork on a courthouse wall of a judge beating a protester was that it had to go. Unlike the elusive artist's other provocative works that are sometimes stolen or carefully removed and displayed in galleries or sold at auction for millions, his latest mural was being erased Wednesday from the record. The stenciled spray-painting of a protester lying on the ground holding a blood-splattered placard while a judge in a traditional wig and black gown beats him with