(VIDEO-AT-LINK) Roaming gangs of black youths descended on a festival in Cincinnati, carrying out a number of attacks that resembled the “Knockout Game,” a nationwide phenomenon in which randomly selected victims are struck in the head, sometimes fatally. In one attack, Sunday night, about 20 black teen girls kicked, stomped on and punched a man who was trying to catch a bus. WKRC-TV in Cincinnati reported David Manz, who is white, was heading to his night shift at Dunkin Donuts when the girls attacked and left him with bruises, scrapes and broken ribs. “They ran straight at me and attacked...