"The government learned from its mistake and adapted to confront a new enemy: a terror network capable of orchestrating attacks across the world. It launched a number of counter-measures, including a bulk telephony metadata collection program - a wide net that could find and isolate gossamer contacts among suspected terrorists in an ocean of seemingly disconnected data," he said.
"This blunt tool only works because it collects everything," Pauley said. "The collection is broad, but the scope of counterterrorism investigations is unprecedented."
Pauley dismissed a lawsuit brought by the American Civil Liberties Union, which promised to appeal to the 2nd U.S. Circuit Court of Appeals in Manhattan.
"We're obviously very disappointed," said Brett Max Kaufman, an attorney with the ACLU's National Security Project. "This mass call tracking program constitutes a serious threat to Americans' privacy and we think Judge Pauley is wrong in concluding otherwise."
Justice Department spokesman Peter Carr said: "We are pleased the court found the NSA's bulk telephony metadata collection program to be lawful."