What a difference the daylight makes. The Foreign Intelligence Surveillance Court, the star chamber charged with applying a thin coat of legality to the constitutionally rickety house the NSA built, secretly approved mass collection of Americans' telephone data 35 times. But once the dragnet was dragged into a regular court - the kind that hears arguments from all two sides and publishes opinions in visible ink - it was declared the Orwellian misadventure that common sense suggested it was.

In a ruling last week that could mark the start of a welcome turn away from the nation's overzealous post-9/11 surveillance stance, U.S. District Judge Richard J. Leon found that the National Security Agency's all-encompassing phone database likely violates Fourth Amendment protections against unreasonable search and seizure. As he noted, the agency has collected the data "without any particularized suspicion of wrongdoing" and rooted through it almost at will.

A few days after the ruling, a presidential panel expressed similar concerns about that and other NSA practices revealed by contractor-on-the-loose Edward Snowden. Noting that "free nations must protect themselves" but also "remain free," the group recommended reasonable precautions such as keeping communications data in private hands, subject to examination only by court order.

Though preliminary, and subject to appeal, Leon's ruling deconstructs the absurd reasoning that erected the NSA's vast database on the modest foundation of Smith v. Maryland, a 1979 Supreme Court decision that allowed cops chasing a robber to monitor a single phone line for a couple of weeks.

Besides the yawning factual chasm between that and today's wholesale snooping, Leon noted the telephone's transformation into something that would not have been recognizable in 1999, let alone 1979. Modern smartphones are distant descendants of the touch-tones of yore, more ubiquitous, intimate, and revealing. "When do present-day circumstances . . . become so thoroughly unlike those considered by the Supreme Court 34 years ago that a precedent like Smith simply does not apply?" he wrote. "The answer, unfortunately for the government, is now."

An appointee of George W. Bush - whose escalation of espionage has been continued and even expanded by President Obama - Leon also pointed out that despite the undoubted importance of counterterrorism efforts, the government provided little evidence that the NSA database makes America safer.

Quite the contrary: "The author of our Constitution, James Madison, who cautioned us to beware 'the abridgment of freedom of the people by gradual silent encroachments by those in power,' would be aghast," Leon wrote.

It's fitting that Philadelphia, the city that produced the founding document, also gave us the plaintiff in this case, Charles Strange, and his activist lawyer, Larry Klayman. The father of an NSA cryptologist killed in Afghanistan, Strange suspects his criticism of the government led to monitoring of his communications. Such fears are inevitable amid unrestrained surveillance.