In Naples, a new kind of gang rules the streets: the 'Paranze', groups of teenage boys who divide their time between Facebook and patrolling the streets armed with pistols and AK-47s, terrorizing local residents in order to mark out the territories of their Mafia bosses. Roberto Saviano's eye-opening novel The Piranhas tells the story of the rise of one such gang and its leader, Nicolas. The first novel by the author of 'Gomorrah'.