Win McNamee/Getty Images U.S. Attorney General Eric Holder, right, and FBI Director Robert Mueller at a news conference on Oct. 11, 2011.

The FBI has dramatically increased its use of a controversial provision of the Patriot Act to secretly obtain a vast store of business records of U.S. citizens under President Barack Obama, according to recent Justice Department reports to Congress. The bureau filed 212 requests for such data to a national security court last year – a 1,000-percent increase from the number of such requests four years earlier, the reports show.

The FBI’s increased use of the Patriot Act’s “business records” provision — and the wide ranging scope of its requests -- is getting new scrutiny in light of last week’s disclosure that that the provision was used to obtain a top-secret national security order requiring telecommunications companies to turn over records of millions of telephone calls.

Taken together, experts say, those revelations show the government has broadly interpreted the Patriot Act provision as enabling it to collect data not just on specific individuals, but on millions of Americans with no suspected terrorist connections. And it shows that the Foreign Intelligence Surveillance Court accepted that broad interpretation of the law.

“That they were using this (provision) to do mass collection of data is definitely the biggest surprise,” said Robert Chesney, a top national security lawyer at the University of Texas Law School. “Most people who followed this closely were not aware they were doing this. We’ve gone from producing records for a particular investigation to the production of all records for a massive pre-collection database. It’s incredibly sweeping.”

The Justice Department and FBI did not respond to requests for comment. But in a recent interview with NBC News, Director of National Intelligence James Clapper dismissed the idea that the records were being used to spy on innocent Americans. “The notion that we’re trolling through everyone’s emails and voyeuristically reading them, or listening to everyone’s phone calls is, on its face, absurd,” he said. “We couldn’t do that even if we wanted to.”

But little-noticed statements by FBI Director Robert Mueller in recent years – as well as interviews with former senior law enforcement officials – hint at what Chesney calls a largely unnoticed “sea change” in the way the U.S. government collects data for terrorism and other national security investigations.

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The Patriot Act provision, known as Section 215, allows the FBI to require the production of business records and any other “tangible things” -- including “books, records, papers, documents and other items,” for an authorized terrorism or foreign intelligence investigation. The Patriot Act was a broad expansion of law enforcement powers enacted by Congress with overwhelming bipartisan support in the aftermath of the Sept. 11, 2001, terrorist attacks. In addition to Section 215, other provisions expanded the FBI’s power to issue so-called “national security letters,” requiring individuals and business to turn over a more limited set of records without any court order at all.

In contrast to standard grand jury subpoenas, material obtained under both Section 215 orders and national security letters must be turned over under so-called “gag orders” that forbid the business or institution that receives the order from notifying its customers or publicly referring to the matter.

From the earliest days of the Patriot Act, Section 215 was among the most hotly disputed of its provisions. Critics charged the language – “tangible things” -- was so broad that it would even permit the FBI to obtain library and bookstore records to inspect what citizens were reading.

Ashcroft confronted criticism

Largely to tamp down those concerns, then-Attorney General John Ashcroft declassified information about the FBI’s use of the provision in September 2003, saying in a statement that “the number of times Section 215 has been used to date is zero.” Ashcroft added that he was releasing the information “to counter the troubling amount of public distortion and misinformation” about Section 215.

But in the years since, the FBI’s use of Section 215 quietly exploded, with virtually no public notice or debate. In 2009, as part of an annual report to Congress, the Justice Department reported there had been 21 applications for business records to the Foreign Intelligence Surveillance Court (FISC) under Section 215 – all of which were granted, though nine were modified by the court. (The reports do not explain how or why the orders were modified.)

In 2010, the number of requests jumped to 205 (all again granted, with 176 modified.) In the latest report filed on April 30, the department reported there had been 212 such requests in 2012 – all approved by the court, but 200 of them modified.

These sharp increase in the use of Section 215 has drawn little attention until now because the number of national security letters (NSLs) issued by the bureau has been so much greater -- 15,229 in 2012. But FBI Director Mueller, in little-noticed written responses to Congress two years ago, explained that the bureau was encountering resistance from telecommunications companies in turning over “electronic communication transaction” records in response to national security letters.

“Beginning in late 2009, certain electronic communications service providers no longer honored NSLs to obtain” records because of what their lawyers cited as “an ambiguity” in the law. (What Mueller didn’t say was this came at a time when all the major telecommunications companies were still facing lawsuits over their cooperation with the government on surveillance programs.) As a result, Mueller said, the FBI had switched over to demanding the same data under Section 215. “This change accounts for a significant increase in the volume of business records requests,” Mueller wrote.

What was not explained at the time, Chesney notes, is that the FBI was using the Section 215 requests to obtain a broad array of records. For example, a top-secret FISC order disclosed last week by the Guardian showed that the FBI had used a single Section 215 request to direct Verizon to turn over “all call detail records or telephony metadata’’ of its customers for a three month period, literally millions of records.

Saying they wanted to put an end to “secret law, eight U.S. senators — led by Sens. Jeff Merkley, D-Ore., and Mike Lee, R-Utah — on Tuesday introduced a bill to require the Justice Department to declassify national security court decisions that have permitted the use of the “business records” provision for such purposes.

That followed a court filing Monday by the American Civil Liberties Union and allied groups asking the surveillance court to release its classified legal opinions question that have allowed the expanded use of Section 215.

The motion, filed “pursuant to the First Amendment,” the ACLU states, and under rules that, in some circumstances, permit petitions to the FISC, also cites statements by two Democratic U.S. senators, Ron Wyden of Oregon and Mark Udall of Colorado, and Obama to justify public disclosure.

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“When the American people find out how their government has secretly interpreted the Patriot Act, they will be stunned and they will be angry,” it quoted Wyden as saying in 2011.

It also cited Obama words after last week’s disclosure of the Verizon order: “I welcome this debate.”

The motion also asks the court to consider the constitutionality of the “gag order” written into Section 215.

“There should be no room for secret law,” said Jameel Jaffer, the ACLU’s deputy legal director, adding that disclosure of the FISC rulings is essential if the debate Obama called for is to take place. “The public has a right to know what limits apply to the government’s surveillance authority, and what safeguards are in place to protect individual privacy.”

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