Forty years in, the War on Drugs has done almost nothing to prevent drugs from being sold or used, but it has nonetheless created a little-known surveillance state in America's most disadvantaged neighborhoods. Arrest quotas and high-tech surveillance techniques criminalize entire blocks, and transform the very associations that should stabilize young lives--family, relationships, jobs--into liabilities, as the police use such relationships to track down suspects, demand information, and threaten consequences. Alice Goffman spent six years living in one such neighborhood in Philadelphia, and her close observations and often harrowing stories reveal the pernicious effects of this pervasive policing. Goffman introduces us to an unforgettable cast of young African American men who are caught up in this web of warrants and surveillance--some of them small-time drug dealers, others just ordinary guys dealing with limited choices. All find the web of presumed criminality, built as it is on the very associations and friendships that make up a life, nearly impossible to escape.