Last year, NBC News anchorman David Gregory almost got in trouble with the law for waving a 30-round ammunition magazine in front of the camera during an interview with NRA leader Wayne LaPierre on “Meet the Press.” The show was being broadcast from Washington, D.C., where it’s illegal under local law to possess even an empty magazine capable of holding more than 10 rounds of ammo. Irvin Nathan, the Attorney General for the District of Columbia, huddled with staffers to decide whether to make a public example out of Gregory for his very public stunt. But Nathan ended up exercising...