If you’ve been paying attention to surveillance and civil liberties issues over the past fifteen years, you’ve likely learned to recognize a particular pattern. Senator Ron Wyden will occasionally send a public letter that essentially says “hey, I can’t tell you what’s happening because it’s classified, but something really bad is going on and you should all be paying attention.”

A decade ago some dubbed this the Wyden Siren. And when the Wyden Siren goes off, history tells us we should listen. Because every single time he’s done this, he’s eventually been proven right.

On Tuesday, Wyden sent a remarkably short letter to CIA Director John Ratcliffe. The entire substantive content is this:

I write to alert you to a classified letter I sent you earlier today in which I express deep concerns about CIA activities.

That’s it. That’s the whole thing. “Deep concerns about CIA activities.” He can’t say what. He can’t say why. But he’s making damn sure there’s a public record that he raised the alarm.

And if he’s done that, it means something very, very, very bad is happening.

If you’re not familiar with the Wyden Siren, let me walk you through the pattern, because it’s been remarkably consistent.

Back in 2011, Wyden and Senator Mark Udall tried to warn the public that the federal government had secretly reinterpreted the PATRIOT Act to mean something entirely different from what the text actually said. They couldn’t reveal the details because they were classified, but Wyden made the situation clear:

We’re getting to a gap between what the public thinks the law says and what the American government secretly thinks the law says.

For a couple years, civil liberties advocates were left guessing what that secret interpretation might be. Then Ed Snowden came along and revealed the NSA’s bulk metadata collection program—the exact thing Wyden had been warning about. Apparently, one of the things that reportedly pushed Snowden to leak was watching then Director of National Intelligence, James Clapper, lie to Wyden’s face in a hearing about whether the NSA was collecting data on millions of Americans. Wyden knew the answer. Clapper lied anyway. Snowden had the proof.

In 2015, Wyden was at it again, this time warning about a secret Justice Department legal opinion related to cybersecurity legislation:

I remain very concerned that a secret Justice Department opinion that is of clear relevance to this debate continues to be withheld from the public. This opinion, which interprets common commercial service agreements, is inconsistent with the public’s understanding of the law, and I believe it will be difficult for Congress to have a fully informed debate on cybersecurity legislation if it does not understand how these agreements have been interpreted by the Executive Branch.

In 2017, we wrote about the Wyden Siren going off again when Dan Coats, then Director of National Intelligence, gave an answer about Section 702 surveillance that Wyden pointed out was to a different question than the one he’d actually asked:

That was not my question. Please provide a public response to my question, as asked at the June 7, 2017, hearing.

The pattern repeats. Wyden asks a specific question about surveillance. The intelligence community answers a slightly different question in a way that technically isn’t lying but is designed to mislead. Wyden calls them out. Eventually, the truth comes out, and it’s always worse than people assumed.

It’s not just surveillance, either. Wyden has used this same approach to expose ICE illegally collecting millions of Americans’ financial records through bulk administrative subpoenas—a program that was hastily shut down the moment Wyden’s office started asking questions about it. He’s caught the government gathering push notification data from Apple and Google while forbidding those companies from telling anyone about it. He’s questioned domain seizures, the FBI’s power to look at your browsing history without a warrant, and countless other government activities that were happening in secret.

The track record here is essentially perfect. When Wyden sends a cryptic letter or asks a pointed question suggesting something concerning is happening behind the classification curtain, something concerning is absolutely happening behind the classification curtain.

So what’s happening at the CIA that has Wyden sending a two-sentence letter that amounts to “I legally cannot tell you what’s wrong, but something is very wrong”?

We don’t know yet. That’s the whole point of classification—it keeps the public in the dark about what their government is doing in their name. But Wyden’s letter is the equivalent of a fire alarm. He’s seen something. He can’t say what. But he wants there to be a record that he raised the concern.

Given the current administration’s approach to, well, everything, the possibilities are unfortunately vast. Is it about domestic surveillance? Something about current ODNI Tulsi Gabbard? International operations gone sideways? Some new interpretation of the CIA’s authorities that would make Americans’ hair stand on end if they knew about it? We’re left guessing, just like we were guessing about the PATRIOT Act’s secret interpretation back in 2011.

But here’s what we do know: Ron Wyden has been doing this for at least fifteen years. And every single time, he’s been vindicated. The secret programs were real. The abuses were real. The gap between what the public thought was happening and what was actually happening was real.

The Wyden Siren is blaring. Pay attention.