Xenophobes in homogenous European countries often complain that immigrants will erase their most precious cultural norms. The race riots in southern Italy last weekend may be one indicator that change is inevitable, as African immigrants who don’t live by the country’s infamous omert code of silence violently protested against the powerful Mafia clans that control their lives, says Roberto Saviano, author of Gomorrah, an anti-Mob book that earned him both critical praise and a 24-hour police guard.