The advent of crack in the 1980s led to a proliferation of highly visible drug markets in New York and other large US cities and an epidemic of violence associated with dealing. In response to public demands to deal with this situation, the police increasingly began to focus their efforts on street-level dealing. They pursued a variety of methods to disrupt dealing, including undercover “buy and bust” and “reverse buy” operations, and drug crackdowns or sweeps involving the saturation of drug markets with police presence.