NEW YORK — The U.S. government has defended its use of a phone-tracking program that collects the telephone records of millions of Americans in a letter to a federal judge, saying it is a program monitored by all three branches of government that is necessary to learn the contacts of known or suspected terrorists and thwart terrorism.
The letter sent Thursday by assistant U.S. attorneys in Manhattan said the "highly sensitive and, in many respects, still classified intelligence-collection program" required the collection and storage of a large volume of information about unrelated communications to fight terrorism.
The letter, the first government response to a lawsuit filed by the American Civil Liberties Union against the Obama administration earlier this year, said the program "fills an intelligence gap highlighted by the attacks of 9/11" and had been repeatedly approved by multiple judges.
It said that under the program, the FBI obtains authorization from the Foreign Intelligence Surveillance Court to collect data from certain telecommunications service providers.
It said the National Security Agency archives the information and "queries the data, when strict standards are met" to detect communications between foreign terrorist organizations and their potential operatives in the United States, providing leads to the FBI or others in the intelligence community for counterterrorism purposes.
"The program has contributed to the disruption of multiple potential terrorist attacks in the United States and abroad," according to the letter.
The ACLU had asked a judge to find the program unconstitutional, saying the government's program exceeds the congressional authority provided by the Patriot Act, which Congress hurriedly passed after 9/11 and reauthorized in 2005 and 2010. President Barack Obama has defended the program and said privacy must be balanced with security.
In its letter, the government said the FISA Court's orders strictly limit the nature of the data the government can collect and the extent to which it can be reviewed.