FROM 2013 to 2015 , the NSA and CIA doubled the number of warrantless searches they conducted for Americans’ data in a massive NSA database ostensibly collected for foreign intelligence purposes, according to a new intelligence community transparency report.

The estimated number of search terms “concerning a known U.S. person” to get contents of communications within what is known as the 702 database was 4,672 — more than double the 2013 figure.

And that doesn’t even include the number of FBI searches on that database. A recently released Foreign Intelligence Surveillance Court ruling confirmed that the FBI is allowed to run any number of searches it wants on that database, not only for national security probes but also to hunt for evidence of traditional crimes. No estimates have ever been released of how often that happens.

Under Section 702 of the Foreign Intelligence Surveillance Act, the NSA collects hundreds of millions of digital communications at rest and in transit from the major internet backbones running in and out of the U.S., as well as from Google, Facebook, YouTube, and other companies, involving “targets” overseas.

Americans’ communications are constitutionally protected from warrantless searches, but when those communications are swept up by the NSA “incidentally” to its main goal, those protections have been essentially ignored.

The Office of the Director of National Intelligence has said the practice of searching the database for American communications is not “unlawful” because the content is collected legitimately in the first place — and because there are protections against sharing Americans’ identities unless it’s absolutely necessary.

But many privacy activists, as well as lawmakers including Sen. Ron Wyden, D-Ore., and Rep. Thomas Massie, R-Ky., describe this practice as a “backdoor” search because it’s a way to gather evidence on Americans without getting court approval.

“If intelligence officials are deliberately searching for and reading the communications of specific Americans, the Constitution requires a warrant,” said Wyden in a press release in June 2014.

The ODNI director of legislative affairs, Deidre M. Walsh, wrote in a 2013 letter to Wyden that the NSA approved 198 searches, or “queries,” for the content of American communications in the 702 database — while the CIA approved “fewer than 1900” queries — for about 2100 overall.

That’s the number that more than doubled in 2015. But the ODNI doesn’t make its transparency reports easy to understand, leaving open the possibility of misinterpretation. For instance, the 2015 figure includes “recurring queries” — basically searches using the same terms more than once. In 2013, the NSA said its estimate “may” have included repeated queries counted individually. That could account for some of the increase between 2013 and 2015.

However, the number of queries for metadata — information about who the communications are to and from, and so on, rather than their content — also went up dramatically.

According to the 2014 letter to Wyden, NSA conducted “approximately 9,500 queries” of American metadata in 2013, including repeated queries — and excluding CIA searches, because the agency doesn’t track that information.

In 2015, the ODNI reported 23,800 searches on metadata — excluding “one IC element” that couldn’t provide statistics — presumably the CIA.

“The number of backdoor searches doubling since last reported shows that warrantless Section 702 surveillance is a significant and growing problem for Americans,” Jake Laperruque, privacy fellow at The Constitution Project, wrote in a message to The Intercept after reading the new report.

The missing data from the FBI is of great concern to privacy advocates. The USA Freedom Act, passed in June 2015, “conspicuously exempts the FBI” from disclosing how often it searches the 702 database, the Project on Government Oversight (POGO) wrote in a letter to the Director of National Intelligence, James Clapper, in October 2015.

“There is every reason to believe the number of FBI queries far exceeds those of the CIA and NSA,” POGO wrote. “To present a fair overview of how foreign intelligence surveillance is used, it is essential that you work with the attorney general to release statistics on the FBI’s use of U.S. person queries.”

The new report also leaves unanswered how many Americans’ communications are collected in the first place.

Fourteen lawmakers on the House Judiciary Committee sent Clapper a letter on April 22 demanding to know how often programs authorized under Section 702 vacuum up communications belonging to innocent Americans. Others, including Sen. Wyden, members of the Privacy and Civil Liberties Oversight Board, and dozens of civil liberties activist groups have been asking the same question for years.

Clapper recently said he is working to provide an estimate on the number of Americans caught up in the dragnet.