Pauley's decision contrasts with a ruling earlier this month by U.S. District Judge Richard Leon, who granted a preliminary injunction against the collecting of phone records of two men who had challenged the program. The Washington, D.C., jurist said the program likely violates the U.S. Constitution's ban on unreasonable search. The judge has since stayed the effect of his ruling, pending a government appeal.
Pauley said the mass collection of phone data "significantly increases the NSA's capability to detect the faintest patterns left behind by individuals affiliated with foreign terrorist organizations. Armed with all the metadata, NSA can draw connections it might otherwise never be able to find."
He added: "As the Sept. 11 attacks demonstrate, the cost of missing such a threat can be horrific."
Pauley said the attacks "revealed, in the starkest terms, just how dangerous and interconnected the world is. While Americans depended on technology for the conveniences of modernity, al-Qaida plotted in a seventh-century milieu to use that technology against us. It was a bold jujitsu. And it succeeded because conventional intelligence gathering could not detect diffuse filaments connecting al-Qaida."
The judge said the NSA intercepted seven calls made by one of the Sept. 11 hijackers in San Diego prior to the attacks, but mistakenly concluded that he was overseas because it lacked the kind of information it can now collect.
Still, Pauley said such a program, if unchecked, "imperils the civil liberties of every citizen" and he noted the lively debate about the subject across the nation, in Congress and at the White House.
"The question for this court is whether the government's bulk telephony metadata program is lawful. This court finds it is. But the question of whether that program should be conducted is for the other two coordinate branches of government to decide," he said.
A week ago, President Barack Obama said there may be ways of changing the program so that is has sufficient oversight and transparency. The ACLU sued earlier this year after former NSA analyst Edward Snowden leaked details of the secret programs that critics say violate privacy rights.
The NSA-run programs pick up millions of telephone and Internet records that are routed through American networks each day.
Pauley said the fact that the ACLU would never have learned about an order authorizing collection of telephony metadata related to its telephone numbers but for Snowden's disclosures added "another level of absurdity in this case."