Amazing report in the WSJ.

The National Security Agency’s ability to gather phone data on millions of Americans hinges on a secret court ruling that redefined a single word: “relevant.”

The National Security Agency’s ability to gather phone data on millions of Americans hinges on the secret redefinition of the word “relevant.”

This change—which specifically enabled the surveillance recently revealed by former NSA contractor Edward Snowden—was made by the secret Foreign Intelligence Surveillance Court, a group of judges responsible for making decisions about government surveillance in national-security cases. In classified orders starting in the mid-2000s, the court accepted that “relevant” could be broadened to permit an entire database of records on millions of people, in contrast to a more conservative interpretation widely applied in criminal cases, in which only some of those records would likely be allowed, according to people familiar with the ruling.

The ‘relevant’ language was added to the Patriot Act when it came up for reauthorization; it was signed by President Bush in 2006.

In interviews with The Wall Street Journal, current and former administration and congressional officials are shedding new light on the history of the NSA program and the secret legal theory underpinning it. The court’s interpretation of the word enabled the government, under the Patriot Act, to collect the phone records of the majority of Americans, including phone numbers people dialed and where they were calling from, as part of a continuing investigation into international terrorism.

“Relevant” has long been a broad standard, but the way the court is interpreting it, to mean, in effect, “everything,” is new, says Mark Eckenwiler, a senior counsel at Perkins Coie LLP who, until December, was the Justice Department’s primary authority on federal criminal surveillance law.