From CNN:
WASHINGTON (CNN) -- The FBI has been covertly monitoring mosques and Muslim homes and businesses in U.S. cities for abnormal radiation levels since 2002, several government officials confirmed Friday.
One government official said the authorities don't obtain warrants because the testing is conducted from outside the buildings on what they consider public property.
An official with the Federal Bureau of Investigation said that none of the FBI's programs target gathering places of any specific segment of the population and that non-Muslim sites were also monitored for radiation.
A Muslim advocacy group has said that the program is "misguided" and targets "the wrong people."
"It is a waste of time, it is a waste of resources and it is causing us to be concerned about our citizenship, our constitutional rights," Nihad Awad, executive director of the Council on American-Islamic Relations, told CNN.
Several sources said the covert program is legal because the authorities conduct the testing in areas like parking lots.
"You do not need to be on anyone's property to get radiation levels," one person familiar with the program told CNN. "How close you need to be depends on search techniques, the equipment used and the substance you are looking for."
The source asked not to be identified because of the sensitive nature of the program.
The program is part of an FBI program supported "from a technical standpoint" by the Department of Energy's Nuclear Emergency Support Team, said an administration official, who declined to be identified because of the classified nature of the operation.
The Energy Department refused to comment on the program.
The purpose of the program -- first reported in U.S. News and World Report -- is to find any radioactive material that could be used to make a dirty bomb, which combines radioactive material with conventional explosives to spread radiation over a large area. A dirty bomb is one of the greatest concerns of U.S. counterterrorism officials.
An FBI spokesman said that all of the agency's investigations and operations are lawful, "intelligence-driven" and based on information about criminal or terrorist threats.
"There is no nuclear- or radiation-monitoring program targeting mosques or other places of gathering by Muslim or any other particular group of citizens," said Mike Mason, head of the FBI field office in Washington.
Another government official said agents would weigh additional information -- not just a person's religion -- before deciding to conduct such tests.
"That is not the only criterion," he said.
Most of the testing is conducted in Washington because the nation's capital is considered a potential target for such an attack. However, an official said testing also has been conducted in Chicago, Illinois; Detroit, Michigan; Las Vegas, Nevada; Seattle, Washington; and New York City.
The program's activity varies "dependent on a number of factors, such as the information we get from a particular part of the world," one official explained.