The New York Police Department monitored Muslim students at universities far beyond the city limits, including the elite Ivy League colleges of Yale and the University of Pennsylvania, it has emerged.
Police talked with local authorities about professors 300 miles away in Buffalo and even sent an undercover agent on a whitewater rafting trip, where he recorded students' names and noted in police intelligence files how many times they prayed.
Detectives trawled Muslim student websites every day and, although professors and students had not been accused of any wrongdoing, their names were recorded in reports prepared for NYPD commissioner Raymond Kelly.
Asked about the monitoring, police spokesman Paul Browne provided a list of 12 people arrested or convicted on terrorism charges in the United States and abroad who had once been members of Muslim student associations, which the NYPD referred to as MSAs.
Jesse Morton, who this month pleaded guilty to posting online threats against the creators of the animated TV show South Park, had once tried to recruit followers at Stony Brook University on Long Island, Mr Browne said.
"As a result, the NYPD deemed it prudent to get a better handle on what was occurring at MSAs," he said. He said police monitored student websites and collected publicly-available information, but did so only between 2006 and 2007.
"I see a violation of civil rights here," said Tanweer Haq, chaplain of the Muslim Student Association at Syracuse. "Nobody wants to be on the list of the FBI or the NYPD or whatever. Muslim students want to have their own lives, their own privacy and enjoy the same freedoms and opportunities that everybody else has."
In recent months, the Associated Press has revealed secret programmes the NYPD built with help from the CIA to monitor Muslims at the places where they ate, shopped and worshipped. The AP also published details about how police placed undercover officers at Muslim student associations in colleges within the city limits, a revelation that has outraged staff and student groups.
Although the NYPD says it follows the same rules as the FBI, some of its activities go beyond what the agency is allowed to do.
Mr Kelly and New York City mayor Michael Bloomberg have repeatedly said that the police follow only legitimate leads about suspected criminal activity. Yesterday, the mayor's office referred any further comment to the NYPD. The latest documents mention no wrongdoing by any students.