U.S. District Court Judge Richard Leon heard arguments Monday for and against a preliminary injunction that could halt dragnet data-collection programs operated by the National Security Agency.

Leon gave Department of Justice attorneys and Larry Klayman, a former Reagan administration prosecutor suing to stop surveillance programs, until Nov. 26 to submit supplementary information, after which he will rule on the injunction request.

"I don't know, frankly, how I'm going to come out," Leon said after hearing arguments in his Washington, D.C., courtroom. "I'm not kidding myself... it's going to the court of appeals and probably to the Supreme Court – one way or the other."

In one of the most substantive exchanges, Leon said Smith v. Maryland – a 1979 Supreme Court case often cited by defenders of surveillance programs – may be outdated.

That landmark ruling found a criminal defendant did not have a reasonable expectation of privacy over a list of phone numbers dialed within a two-day period.

"Things have changed a little since ‘79," Leon said. "The technology that was being used in that case," he said, "paled in comparison, paled in comparison to the technology the NSA has at its disposal."

Leon pointed to the Supreme Court's 2012 U.S. v. Jones decision, which imposed limits on police use of GPS tracking, as a more modern legal barometer. "Smith's value may be very limited [here]," Leon told government attorneys.

"Smith remains the law and it's controlling here," responded Department of Justice lawyer James Gilligan.

Klayman filed two lawsuits in June after the NSA's widespread spying programs were exposed by whistle-blower Edward Snowden. One suit targets the collection of all Verizon phone records and the other seeks to end the PRISM Internet surveillance program. Leon is considering injunction requests for each of the programs.

Leon noted that the Klayman lawsuits are part of a flurry of legal activity. U.S. District Court Judge William Pauley is hearing arguments Friday in New York about a preliminary injunction sought by the American Civil Liberties Union against the NSA's collection of phone records. On Monday the U.S. Supreme Court denied a bid from the Electronic Privacy Information Center for fast-track review of the phone data-collection program.

During the hearing Leon expressed concern about two areas of law. First, he questioned his authority to review Foreign Intelligence Surveillance Court decisions. The law establishing that court doesn't provide for review by a U.S. District Court, he said. Leon also questioned whether the plaintiffs have standing to sue - an issue that derailed a case brought before the U.S. Supreme Court last year by Amnesty International.

On standing, Klayman said a leaked FISC order showed his clients' Verizon phone records were collected, giving them standing.

Gilligan disagreed. That court order actually required a Verizon corporate entity that does not directly route calls to hand over information, he said, not Verizon Wireless – the provider used by plaintiffs.

"The government has not acknowledged the identity of any carrier," he said.

"If the government holds all the cards," Leon asked, "they could never establish standing, could they?"

Gilligan said that's accurate and pointed to the Supreme Court's rejection of the Amnesty International case.

Gilligan also said a preliminary injunction is unnecessary because there's no risk of imminent harm to the plaintiffs, citing a vigorous oversight framework for NSA database queries. "FISC doesn't have the capacity or manpower to oversee anything," Leon piped in.

Leon expressed concern about his authority to declare unconstitutional the decisions of 15 federal judges serving on the FISC who authorized the NSA collection of phone records, but Klayman argued he has the authority – and responsibility – to do so.

"King George [III] had judges too," Klayman said. "You, your honor, are the last bastion of protection for the American people. [We are] going into the only court we can be in."

Klayman argued that because the law doesn't explicitly prohibit a U.S. District Court from reviewing FISC decisions, it's possible to do so. "The fact that it's not in there does not preclude another option for relief," he said.

Gilligan disagreed, pointing to a special appeals court for FISC and the possibility of Supreme Court review.

Throughout his arguments Klayman denounced the FISC as a "star chamber" where decisions are made secretly and without adequate debate.

FISC decisions authorizing the collection of all phone records from major phone carriers were classified and unknown to the public until the Snowden leaks.

Klayman argues the NSA lacks authority under Section 215 of the Patriot Act to collect the phone records – which are held for 5-year periods – and lacks authority under Section 702 of the Foreign Intelligence Surveillance Act to conduct its PRISM program. The ACLU is making the same claim in its phone record case.

"Simply hold the government to the letter of the law," Klayman said. At one point during the hearing, Leon pondered, "Is it really that simple?"