Over the past decade, news reports and movies have made a broad public increasingly familiar with urban gangs' colors, hand signals, and rap refrains. But to most Americans, the gangs are anything but picturesque. They have emerged as a symbol of a fearsome and depressed urban America and of American economic and moral decline. Gang murders and drug-dealing seem to confirm many Americans' worst suspicions about the dangerous poor, including the idea that self-destructive behavior is now the main cause of poverty. Consequently, the social understanding of gangs is central to the larger debate today about what obligations, if any, Americans recognize toward the poor.