Subsequent to the terrorist attacks of September 11 , 2001 , the New York City Police Department developed a large and sophisticated array of surveillance technologies , generating large collections of data including billions of license plate readings and weeks of security footage from thousands of cameras . This data is now used in the department 's day-to-day operations , from counter-terrorism investigations to resolving domestic violence complaints . The system consists of an interconnected web of CCTV cameras , license plate readers , physical sensors , machine learning software , data analytics dashboards , and mobile apps
terrorist attacks of September 11 , 2001
September 11 attacks
Police surveillance in New York City