In 2004, an underground rap DVD entitled "Stop Snitching" appeared on the crime-ridden streets of inner-city Baltimore. A rash of "Stop Snitching" t-shirts soon spread through dozens of American cities, including Boston, New York, Pittsburgh, and Milwaukee. The DVD and T-shirts admonished criminal informants - often younger, black men involved in drug dealing - for ratting out their peers in exchange for leniency. In fact, this underground debate reflected a little-known national problem. In waging the wars on drugs and crime, police and prosecutors commonly allow their informants to continue committing crime in their home communities. Alexandra Natapoff argues that this practice has produced few positive results, and instead generates bad information, endangers innocent people, allows criminals to avoid punishment, compromises the integrity of police work, and incites violence and distrust in socially and economically vulnerable neighbourhoods. Snitching is the first comprehensive analysis of the powerful impact of criminal informant use throughout the American legal system and beyond. It exposes the social destruction caused by criminal snitching in some poor, high-crime African American neighbourhoods, and how the practice renders the entire penal process more secretive and less fair. Driven by dozens of real life stories and tragedies, Natapoff explores the legal, political, and cultural significance of snitching: from the war on drugs to hip hop music, from the FBI's mishandling of its murderous mafia informants to the new surge in white collar and terrorism informing. She explains how existing law functions and proposes new reforms. By delving into the secretive world of criminal snitching, Natapoff reveals deep and often disturbing truths about the way American justice really works.