WASHINGTON: A Federal District Court judge ruled this week that the National Security Agency’s collection and storage of all Americans’ phone records probably violates the United States’ Constitution and is an ‘almost Orwellian’ system that ‘surely . . . infringes on ‘that degree of privacy’ that the founders enshrined in the Fourth Amendment”.

It’s the first successful legal challenge to NSA surveillance since June, when Edward Snowden began a cascade of NSA disclosures. It might just set up the most important legal debate about surveillance and personal privacy in decades. And it threatens to undermine one of the major legal foundations of the NSA’s vast surveillance network.

Judge Richard Leon of the District of Columbia, a George W Bush appointee, ordered the government to stop collecting the phone records of two plaintiffs who brought a lawsuit against the NSA’s so-called metadata programme and to destroy the information it has on them now. He stayed his injunction, pending an almost certain appeal by the Obama administration. But if the case is eventually heard by an appeals court — and there are reasons to think it will be — it would be the highest-stakes and highest-profile battle to date over the NSA’s programme, and a proxy argument for the broader ethical dimensions about massive government surveillance.

The judge ruled that the government’s collection of phone records relied on an outdated Supreme Court ruling, from 1979, that metadata isn’t protected by the Fourth Amendment. “The ubiquity of phones has dramatically altered the quantity of information that is now available and, more importantly, what that information can tell the government about people’s lives,” the judge wrote. “I cannot possibly navigate these uncharted Fourth Amendment waters using as my North Star a case that predates the rise of cell phones.”

But that case, Smith v. Maryland, is part of the foundation of NSA’s global surveillance system, which relies on the collection of all kinds of metadata — from phone records, to email header information, to Internet addresses. Leon’s ruling may be the first step towards bringing that issue before the America’s highest court, and potentially altering the way the global surveillance system is run.

In some respects, momentum has been building towards this moment. The metadata programme was nearly defanged over the summer, in a rare show of bipartisan support in the House of Representatives. Since then, there have been further revelations of government spying, including on US allies, and a presidential review panel has reportedly recommended a sweeping set of reforms at the NSA, including prohibiting the agency from storing Americans’ phone records. Since June, the Obama administration has mounted a public relations offensive in support of the NSA programme and has told lawmakers that it is legal and necessary to protect Americans from terrorist attacks — an argument that Judge Leon found unpersuasive. But officials have rarely had to publicly argue the legality and constitutionality of the programme in court. The only judges to review the programme have done so in secret over the past six years, and no lawyer has been present to argue that the programme should be changed or discontinued.

In finding that the metadata programme probably violates the Fourth Amendment, Judge Leon ruled on broad grounds, leaving the DC Court of Appeals a number of potential options. They could dismiss the case — ruling, as previous courts have, that the plaintiffs lack standing to bring the suit because they can’t prove that they were individually subjected to secret surveillance.

But that was before Snowden’s leak, which provided documented evidence that the government was collecting phone records. Administration officials subsequently confirmed the programme exists, and that it continues to collect information about hundreds of millions of Americans. The plaintiffs in the case, led by conservative public-interest attorney Larry Klayman, arguably have the proof of standing that has eluded prior challengers to government surveillance.

The administration would also have a hard time arguing that the need to preserve national security secrets is reason not to hear the case.

“Thanks to Snowden, the government is not really in a position to tell the DC Circuit, ‘You can’t reach the merits [of this case] because of state secrets,” said Stephen Vladeck, a professor at American University’s College of Law who focuses on national security.

Of course, the ruling could end up being short-lived. Paul Rosenzweig, a homeland security official in the Bush administration, called Leon’s ruling “remarkable,” but also “unpersuasive,” and predicted that it wouldn’t stand.

—By arrangement with the Washington Post-Bloomberg News Service