The National Security Agency’s program of collecting telephone-call data is probably illegal, a federal judge ruled, allowing a lawsuit claiming it violates the U.S. Constitution to go forward.

The ruling Monday came a day ahead of President Barack Obama’s meeting with a group of executives including Apple’s Tim Cook and Yahoo’s Marissa Mayer whose companies are pushing the U.S. to curb broad government spying on communications.

The executives intend to press Obama to act on the changes to surveillance policies proposed in a letter sent to the president and lawmakers last week, according to a representative of one of the companies, who asked not to be identified because the meeting plans aren’t public.

Apple and Yahoo were among the companies that signed the letter, which said the U.S. should take the lead in changing government surveillance practices after revelations that the National Security gained access to phone and Internet data networks to conduct spying.

The companies said the balance “in many countries has tipped too far in favor of the state and away from the rights of the individual.”

The meeting is being held as the NSA’s sweep of Internet and telephone data is coming under increased scrutiny from Congress and the courts and as Obama is weighing new limits on such surveillance. Technology companies are facing the loss of billions of dollars in overseas business, stricter regulations and erosion of consumer trust as a result of revelations about the NSA’s surveillance.

First Court Decision

In the first federal court decision to enable a challenge to the surveillance program, U.S. District Judge Richard Leon in Washington said the plaintiffs would probably prevail at trial on their claim that the Constitution’s Fourth Amendment right to privacy outweighs the government’s need to gather and analyze the information.

Leon granted a temporary order blocking the government from collecting what’s known as metadata from the Verizon Wireless accounts of the two plaintiffs, conservative legal activist Larry Klayman and Charles Strange, who in court papers said the U.S. government may have intentionally killed his son in Afghanistan. He also required the U.S. to destroy any such information in the NSA’s possession.

Leon froze the order while the government makes a likely appeal “in light of the significant national security interests at stake in this case and the novelty of the constitutional issues,” according to Monday’s ruling.

The case marks the first time a district court judge has ruled on the NSA program, disclosed this year in leaks by the former agency contractor Edward Snowden. The Foreign Intelligence Surveillance Court, which reviews government requests for permission to engage in electronic surveillance of foreign suspects who may be communicating with U.S. citizens, has said the data collection is constitutional.

Published Accounts

Leon’s ruling addressed motions made in two separate lawsuits, each filed by Klayman – founder of the public interest group FreedomWatch – in the wake of published accounts of NSA surveillance activities revealed by Snowden.

Snowden, sought by the U.S. on criminal charges, is in Russia, which has granted him temporary asylum.

Klayman said he was “elated” with Leon’s decision.

“There are very few judges who have the courage to do what Judge Leon did,” he said. “He’s an American hero.”

Klayman, a practicing lawyer, said the NSA’s actions had made the U.S. into a police state where “you can’t make one phone call, you can’t send any e-mails, because you think the government is watching.” That has chilled rights of free speech and free association, he said.

Justice Department Defends Program

White House press secretary Jay Carney said he hadn’t seen the ruling and referred questions to the Justice Department.

Andrew Ames, a spokesman for the department, said in an e- mail, “We believe the program is constitutional as previous judges have found.” The department is reviewing the decision, he said.

Ed McFadden, a Verizon spokesman, said the company couldn’t immediately comment on the ruling.

U.S. Senator Patrick Leahy of Vermont, a Democrat who chairs the chamber’s Judiciary Committee, said in a statement that he welcomed the decision. His committee has held three hearings in recent months on issues addressed in the litigation, he said.

“This is a very significant ruling,” Kevin Bankston, policy director for the Washington-based Open Technology Institute, a policy and research organization, said in a phone interview. The ruling should have “significant implications” for how the White House and Congress deal with the NSA program, he said.

‘Talking Point’

“It robs the government of its talking point that the courts have never found there to be a meaningful privacy interest in phone records,” he said. “This decision absolutely should shift the debate.”

Leon, an appointee of President George W. Bush, rejected the assertion by President Barack Obama’s administration that Americans don’t have a right to privacy for records showing phone numbers called and the duration of the connection.

The administration, and the foreign intelligence court, have relied on a 1979 Supreme Court ruling that such data isn’t protected by the Fourth Amendment.

“The almost-Orwellian technology that enables the government to store and analyze the phone metadata of every telephone user in the United States is unlike anything that could have been conceived in 1979,” Leon wrote.

‘Suveillance Capabilities’

“When do present-day circumstances — the evolution in the government’s surveillance capabilities, citizens’ phone habits, and the relationship between the NSA and telecom companies — become so thoroughly unlike those considered by the Supreme Court 34 years ago that a precedent like Smith does not apply?” Leon asked. “The answer, unfortunately for the government, is now.”

The judge said that while he accepts without question the Obama administration’s position that combating terrorism is of “paramount importance,” the government offered no explanation as to how removing the records of the two plaintiffs from the NSA’s database would damage that effort.

He also said he was “not convinced at this point in the litigation that the NSA’s database has ever truly served the purpose of rapidly identifying terrorists in time-sensitive investigations.”

The case is Klayman v. Obama, 13-cv-881, U.S. District Court, District of Columbia (Washington).