A National Security Agency system that analyzed logs of Americans’ domestic phone calls and text messages cost $100 million from 2015 to 2019, but yielded only a single significant investigation, according to a newly declassified study.
Moreover, only twice during that four-year period did the program generate unique information that the F.B.I. did not already possess, said the study, which was produced by the Privacy and Civil Liberties Oversight Board and briefed to Congress on Tuesday.
“Based on one report, F.B.I. vetted an individual, but, after vetting, determined that no further action was warranted,” the report said. “The second report provided unique information about a telephone number, previously known to U.S. authorities, which led to the opening of a foreign intelligence investigation.”
The report did not reveal the subject matter of the one significant F.B.I. investigation that was spurred by the Freedom Act program, and it did not divulge its outcome.
But the high expense and low utility of the call records collected sheds new light on the National Security Agency’s decision in 2019 to shutter the program amid recurring technical headaches, halting a counterterrorism effort that has touched off disputes about privacy and the rule of law since the Sept. 11, 2001, attacks.
The information surfaced as Congress was weighing whether to allow the law that authorizes the agency to operate the system — the USA Freedom Act of 2015 — to expire on March 15, or whether to accede to the Trump administration’s request that lawmakers extend the statute, so the agency could choose to turn the system back on in the future.