As questions have swirled for nearly a month about the background of Shaun King, the Black Lives Matter activist has refused all requests for comment and clarification from the media. But he has fought back against the allegations made against him, just behind the scenes. King, 35, has threatened to sue a former high school classmate for slander after he posted and commented on his Facebook page about a Daily Caller article laying out evidence undermining King’s claim that as a high school student in Versailles, Ky. he was attacked by a dozen “redneck” students in a 1995 hate crime....