The National Security Agency (NSA) collected over 530 million phone records of Americans in 2017—that's three times the amount the spy agency sucked up in 2016.

The figures were released Friday in an annual report from the Office of the Director of National Intelligence (ODNI).

It shows that the number of "call detail records" the agency collected from telecommunications providers during Trump's first year in office was 534 million, compared to 151 million the year prior.

"The intelligence community's transparency has yet to extend to explaining dramatic increases in their collection," said Robyn Greene, policy counsel at the Open Technology Institute.

The content of the calls itself is not collected but so-called "metadata," which, as Gizmodo notes, "is supposedly anonymous, but it can easily be used to identify an individual. The information can also be paired with other publicly available information from social media and other sources to paint a surprisingly detailed picture of a person's life."

The report also revealed that the agency, using its controversial Section 702 authority, increased the number of foreign targets of warrantless surveillance. It was 129,080 in 2017 compared to 106,469 in 2016.

As digital rights group EFF noted earlier this year,

Under Section 702, the NSA collects billions of communications, including those belonging to innocent Americans who are not actually targeted. These communications are then placed in databases that other intelligence and law enforcement agencies can access—for purposes unrelated to national security—without a warrant or any judicial review.

"Overall," Jake Laperruque, senior counsel at the Project On Government Oversight, said to ZDNet, "the numbers show that the scale of warrantless surveillance is growing at a significant rate, but ODNI still won't tell Americans how much it affects them."