The criticism is in a lengthy secret ruling that lays bare some of the frictions between the Foreign Intelligence Surveillance Court and U.S. intelligence agencies obligated to obtain the court's approval for surveillance activities.
The ruling, dated April 26 and bearing the label "top secret," was obtained and published Thursday by the news site Circa.
It is rare that such rulings see the light of day, and the lengthy unraveling of issues in the 99-page document opens a window on how the secret federal court oversees surveillance activities and seeks to curtail those that it deems overstep legal authority.
The document, signed by Judge Rosemary M. Collyer, said the court had learned in a notice filed Oct. 26, 2016, that National Security Agency analysts had been conducting prohibited queries of databases "with much greater frequency than had previously been disclosed to the court."
It said a judge chastised the NSA's inspector general and Office of Compliance for Operations for an "institutional 'lack of candor' " for failing to inform the court. It described the matter as "a very serious Fourth Amendment issue."