The New York Police Department secretly opened "terrorism enterprise investigations" into at least 10 of the city's mosques, effectively designating every single congregant as a valid surveillance target. Documents uncovered by the AP show that the NYPD spied on countless Muslims, and even tried to get informants onto the boards of mosques and other Islamic institutions. The department convinced a federal judge to rewrite the rules to allow such tactics in 2003, arguing that mosques could "shield the work of terrorists."
The FBI never used the TEI tool, and it denied NYPD requests to bug mosques, saying it would violate federal law. So the department sent informants into the mosques carrying hidden recording devices instead. In one case, both federal investigators and the NYPD looked into a 26-year-old Salafist whose father was tied to the 1993 World Trade Center attacks. After a number of months, the FBI concluded there was no evidence he was recruiting jihadists. But the NYPD spied on him and his mosque for at least four years—including at his wedding. Such years-long spying efforts were common. For many, many more details, click here.