Secret court rulings have allowed the NSA to gather phone data on millions of Americans, all hinging on the definition of the word “relevant.”  This change in the law came from the Foreign Intelligence Surveillance Court, a secret body of judges who evaluate government surveillance in the name of national security. 

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.

Mark Eckenwiler, senior counsel at Perkins Coie LLP and the Justice Department’s authority on criminal surveillance law explained that ” ‘relevant’ has long been a broad standard, but the way the court is interpreting it, to mean, in effect, ‘everything,’ is new. I think it’s a stretch” of previous federal legal interpretations, says Mr. Eckenwiler, who hasn’t seen the secret ruling. If a federal attorney “served a grand-jury subpoena for such a broad class of records in a criminal investigation, he or she would be laughed out of court.”

According to the Patriot Act, the FBI can require business turn over “tangible things” like records as long as those things are believed to be “relevant to an authorized investigation.” This is a pretty broad standard. 

The Supreme Court has held that things are “relevant” if there is a “reasonable” possibility they will provide information relating to an investigation. In the past, large sets of data did not meet the relevance standard because substantial portions would involve innocent people’s information.

On the other hand, the FISA court has developed its own standards on the issue “centered on the idea that investigations to prevent national-security threats are different from ordinary criminal cases.” These rulings are classified and cannot be challenged.  

Paul Rosenzweig, a former Deputy Assistant Secretary for Policy in the Department of Homeland Security in the Bush administration defended the data grab: “Large databases are effective” for this type of analysis “only to the extent they are actually comprehensive.”  

There are safeguards in place surrounding accessing this data because a query can take place only “when there is a reasonable suspicion, based on specific facts, that the particular basis for the query is associated with a foreign terrorist organization,” according to James Clapper, Director of National intelligence.

The NSA database includes data about people’s phone calls–numbers dialed, how long a call lasted–but not the actual conversations. According to Supreme Court rulings, a phone call’s content is covered by the Constitution’s Fourth Amendment, which restricts unreasonable searches, but the other types of data aren’t.

The rise of digital surveillance came after 9/11 during the Bush administration and has only expanded over the years. Domestic internet surveillance was moved under the purview of the FISA court in 2004 and phone call data followed in 2006.  In 2005-2006, some congressmen tried to tighten up the Patriot Act by moving to a “relevant” standard from the far looser standard of simply asserting those records were needed. Whether there is a significant distinction between these two standards is highly debatable. 

“Relevance is a very broad standard that could arguably justify the collection of all kinds of information about law-abiding Americans,” former Sen. Russ Feingold on the Senate floor in 2006.

Timothy Edgar, a former top privacy lawyer at the Office of the Director of National Intelligence and the National Security Council in the Bush and Obama administrations described the programs evolution: “It wasn’t seen that we’re pushing the boundaries of surveillance law here. It was the very opposite. You’re starting from a huge amount of unilateral surveillance and putting it on a much sounder legal basis.”

In general people assume data collection and surveillance pertain to discrete suspects rather than wholesale acquisition of communication companies’ databases. “The government must request specific records relevant to its investigation,” Rep. Jim Sensenbrenner (R., Wis.), one of the authors of the Patriot Act, says. “To argue otherwise renders the provision meaningless,” he says. “It’s like scooping up the entire ocean to guarantee you catch a fish.”

Ultimately, this is under the authority of Congress, as they could have prohibited “bulk collection of records.”  But then again, since the program is secret, there would be limited public debate.