A senior Democratic lawmaker with knowledge of some of the U.S. government’s most secretive operations has said he has “deep concerns” about certain activities by the Central Intelligence Agency. 

The two-line letter written by Sen. Ron Wyden, the longest serving member of the Senate Intelligence Committee, does not disclose the nature of the CIA’s activities or the senator’s specific concerns. But the letter follows a pattern in recent years in which Wyden has publicly hinted at wrongdoing or illegality within the federal government, sometimes referred to as the “Wyden siren.” 

In a statement (via the Wall Street Journal’s Dustin Volz), the CIA said it was “ironic but unsurprising that Senator Wyden is unhappy,” calling it a “badge of honor.”

When reached by TechCrunch, a spokesperson for Wyden’s staff was unable to comment, as the matter was classified. 

Tasked with oversight of the intelligence community, Wyden is one of a few lawmakers who is allowed to read highly classified information about ongoing government surveillance, including cyber and other intelligence operations. But as the programs are highly secretive, Wyden is barred from sharing details of what he knows with anyone else, including most other lawmakers, except for a handful of Senate staff with security clearance.

As such, Wyden, a known privacy hawk, has become one of the few key members of Congress whose rare but outspoken words on intelligence and surveillance matters are closely watched by civil liberties groups.

Over the past few years, Wyden has subtly sounded the alarm on several occasions in which he has construed a secret ruling or intelligence gathering method as unlawful or unconstitutional.

In 2011, Wyden said that the U.S. government was relying on a secret interpretation of the Patriot Act, which he said — without disclosing the nature of his concerns — created a “gap between what the public thinks the law says and what the American government secretly thinks the law says.” 

Two years later, then-NSA contractor Edward Snowden revealed that the National Security Agency was relying on its secret interpretation of the Patriot Act to force U.S. phone companies, including Verizon, to turn over the call records of hundreds of millions of Americans on an ongoing basis.

Since then, Wyden has sounded the alarm on how the U.S. government collects the contents of people’s communications; revealed that the Justice Department barred Apple and Google from disclosing that federal authorities had been secretly demanding the contents of their customers’ push notifications; and said that an unclassified report that CISA has refused to release contains “shocking details” about national security threats facing U.S. phone companies.

As noted by Techdirt’s Mike Masnick, we may not know yet why Wyden sounded the siren about the CIA’s activities, but every time Wyden has warned, he has also been vindicated.