By Joseph Ax
NEW YORK (Reuters) - The American Civil Liberties Union on Friday urged a federal judge to halt a U.S. spy agency's sweeping collection of telephone data, arguing that the program goes beyond what Congress authorized and violates the constitutional rights of Americans.
"If you accept the government's argument, you are accepting a dramatic expansion in the government's investigative power," Jameel Jaffer, an ACLU attorney, told U.S. District Judge William Pauley in Manhattan.
The U.S. Justice Department argued that the National Security Agency's collection of such "metadata" is permissible under the law and essential to the government's counterterrorism efforts.
"It's authorized by statute, and it's constitutional," said Justice Department lawyer Stuart Delery, who asked Pauley to throw out the ACLU's lawsuit.
Pauley did not say when he will rule.
The ACLU filed its legal challenge in June, soon after U.S. officials acknowledged that the NSA spy agency is gathering metadata - the phone numbers called and the time and duration of each call - of Americans' phone calls from the nation's telecommunications providers.
The vast program's existence was first disclosed by Edward Snowden, the former NSA contractor who faces criminal charges in the United States. Snowden is living in Russia, where he was granted asylum in August for at least a year.
Snowden's leaks, which have detailed the breadth of the U.S. government's electronic surveillance efforts, sparked an ongoing debate over how far government agencies should go in order to protect Americans from attack.
President Barack Obama has defended the surveillance programs but indicated a willingness to consider constraints, particularly following the furor over allegations that the NSA tapped German Chancellor Angela Merkel's mobile phone and conducted widespread data collection in Europe.
The arguments centered on Section 215 of the Patriot Act - passed after the September 11, 2001, attacks on the United States - that expanded the government's investigative powers to combat threats from militant groups.
Delery emphasized that Congress had reauthorized the law in 2010 and 2011 after getting briefed on the NSA program.
Pauley questioned that argument, pointing out that Republican U.S. Representative Jim Sensenbrenner had filed court papers saying he had been unaware of the program's scope.
In addition to claiming that the collection goes beyond the Patriot Act's authority, the ACLU said the collection of phone data violates the prohibition against warrantless searches under the Fourth Amendment to the Constitution.
Alex Abdo, an ACLU lawyer, said the call data could reveal when someone phoned his or her doctor, an abortion clinic or even an ex-sweetheart, eviscerating any expectation of privacy.
Delery argued that the mere collection of metadata does not constitute a search. Investigators analyze the data for specific information only when there is a "reasonable and articulable suspicion" of a connection to terrorism, he said.
He also said that the program had made "important contributions" to foiling plots, echoing a point that some officials have made. Several U.S. senators, however, including Democrats Ron Wyden and Mark Udall, have questioned that claim based on classified documents they have seen.
A previous legal challenge to the program by Amnesty International failed at the U.S. Supreme Court in part because the government successfully argued that the group could not prove its data had been collected and thus had no standing to bring the case.
In this case, by contrast, there is no dispute that the ACLU, as a customer of Verizon, has had its phone records taken by the government.
Nevertheless, Delery argued that the ACLU had not shown that it had suffered harm as a result and therefore should be barred from seeking relief.
The case is ACLU et al v. Clapper et al, U.S. District Court for the Southern District of New York, No. 13-3994.
(Reporting by Joseph Ax; Editing by Will Dunham)