Cellphones and other electronic devices are not permitted inside the courtroom where Supreme Court justices hear cases.Even lawyers arguing cases before the justices are forbidden from bringing in their cellphones.Before entering the courtroom, visitors must leave their phones in lockers and pass through metal detectors.During Tuesday morning's arguments in the case of Bristol-Myers Squibb Co. v. Superior Court of California, the ring of a cellphone could be heard.Justice Stephen Breyer quickly maneuvered to turn off the device, to his colleagues' amusement.The Associated Press reports: