What began with a concerned mother calling police on her son ended in the thwarting of a terror plot involving drones and snipers aimed at members of U.S. Congress attending Sunday's UFC event at the White House, the government alleges in a criminal complaint filed against one of the plot's admitted leaders, an Ohio teen. Tycen Proper, 19, of Danville, Ohio, told federal investigators on June 11 he intended to "jump-start" a revolution in the U.S. with an attack on June 14 that would begin with drone bombings over the north side of the arena. Co-conspirators, the charging documents allege,...