The findings were the product of a three-month review meant to address concerns expressed by Muslim organizations, who later filed a lawsuit in New Jersey federal court against the NYPD for unfairly targeting the Muslim community.

U.S. Attorney General Eric Holder in March called reports of NYPD surveillance "disturbing," though White House chief counterterrorism adviser John Brennan praised the city's efforts to strike a balance between security and the protection of civil rights.