Should a lawyer defend only 'good' people?

That's what Charles Stimson, the deputy assistant secretary of defense for detainee affairs, apparently thinks. He's upset that lawyers from many white-shoe law firms are defending the prisoners at Guantanamo, who come under Mr. Stimson's purview. He is upset to such a degree that he named these firms and suggested that companies should stop hiring them. Perhaps, Mr. Stimson is worried that some of the prisoners may be found innocent.