Once crack was introduced about six years ago, Mandela and the surrounding complex of shantytowns became Rio's main outdoor drug market, a "cracolandia," or crackland, where users bought the rocks, smoked and lingered until the next hit. Hordes of addicts lived in cardboard shacks and filthy blankets, scrambling for cash and a fix. Dealers have stopped selling the drug in Mandela and nearby Jacarezinho in a move that traffickers and others say will spread citywide within the next two years. The drug bosses, often born and raised in the very slums they now lord over, say crack destabilizes their communities.