Sen. Dianne Feinstein (D-Calif.), chair of the Senate Intelligence Committee, leaves the chamber just after saying that the CIA's improper search of a stand-alone computer network established for Congress has been referred to the Justice Department. (J. Scott Applewhite/AP)

Senate Intelligence Committee Chair Dianne Feinstein (D-Calif.) accused the Central Intelligence Agency of an "unauthorized search" of her committee's computers today — while the committee was performing oversight over the CIA itself. In doing the search, she says the CIA potentially violated the separation of powers as enshrined by the constitution, along with federal laws and an executive order.

Wait, that sounds really major. What happened?

This is actually a really long story, but it all starts with "enhanced interrogation."

You mean torture?

Well, President Obama called it that. As one of his first acts in office, President Obama signed an executive order reversing the interrogation and detention practices of the Bush administration. That same year, the Senate Intelligence Committee started work on a study of the CIA's now-defunct interrogation and detention program.

According to The Post's Ellen Nakashima, the 6,300 -page study prepared by the committee supposedly concluded that the harsh interrogation techniques (such as waterboarding) deployed by the CIA failed to produce significant intelligence and the agency misled the public and their congressional overseers about their efficacy at times. The CIA issued a 122-page rebuttal to the committee’s study last June that challenged its specific findings and overall conclusions.

But there's also an internal CIA review, often called the "Panetta Review" because it was started during Leon Panetta's tenure as head of the agency, that some officials say agrees with the committee's findings.  Sen. Mark Udall (D- Colo.) revealed its existence in a December hearing, saying, "it appears that this review ... is consistent with the Intelligence Committee's report, but, amazingly, it conflicts with the official CIA response to the committee's report."  

"If this is true, it raises fundamental questions about why a review the CIA conducted internally years ago and never provided to the committee is so different from the CIA's formal written response to the committee's study," he said, requesting a final version of the review be provided to the Committee.

Can I read any of those documents, maybe decide for myself?

Nope, not unless you have a security clearance. All three documents — the Senate Committee study, the CIA's official response, and the internal Panetta review are currently classified. But members of the committee, including Udall and Feinstein, have urged the declassification of their review. In fact, Udall sent the president a letter about declassification last week that referenced the incident Feinsten is so upset about.

"As you are aware, the CIA has recently taken unprecedented action against the committee in relation to the internal CIA review," wrote Udall, "and I find these actions to be incredibly troubling for the committee's oversight responsibilities and for our democracy."

Enough mystery, what actually happened?

Well, the exact details are still murky, but according to Feinstein the CIA searched computers and networks used by committee staffers preparing their review of CIA detention and interrogation programs. The search appears to have been set off by Udall's December comments and a written request from Feinsten for the final version of the Panetta review, leading the CIA to investigate how the group had learned about the document.

Wait, did the committee staff already have access to the Panetta review?

According to Feinstein, staffers had access to a draft of the review that they found during their investigation using a search tool provided by the CIA. "Our staff involved in this matter have the appropriate clearances, handled this sensitive material according to established procedures and practice to protect classified information, and were provided access to the Panetta Review by the CIA itself," according to Feinstein.

She also indicated that some documents had stop being accessible through the CIA search tool,  perhaps including those draft versions of the Panetta review, but staffers had printed out or locally saved versions to their own systems.

But back to the alleged search. According to Feinstein, the CIA and the committee had agreed that staffers working on the report could review CIA documents only at a CIA black site in Northern Virginia, but that their system would be set up separately from the primary CIA network and for their exclusive use.

However, in a Jan. 15 meeting, Feinstein says CIA Director John Brennan informed her and Senate Intelligence Committee Vice Chairman Saxby Chambliss (R-Ga.) "that without prior notification or approval, CIA personnel had conducted a search ... of the committee computers at the off-site facility." That search allegedly included not just an audit of the CIA documents available to the staff, but also their own internal work products and communications.  She also says Brennan indicated that he would be ordering "further forensic investigation of the committee network" to learn more about the oversight staff's actions.

Feinstein said neither she nor her committee's staff were ever asked how they obtained information about the Panetta review. "In place of asking any questions, the CIA's unauthorized search of the committee computers was followed by an allegation, which we now have seen repeated anonymously in the press, that the committee staff had somehow obtained the document through unauthorized or criminal means, perhaps to include hacking into the CIA's computer network."

She also said the CIA's acting general counsel filed a criminal report regarding committee member's access to the document to the Department of Justice.

The CIA filed a criminal report on the people doing an oversight investigation about a CIA program? 

Yes. Actually, to make it all the more awkward, the acting general counsel was previously a lawyer for the CIA's counterterrorism center — the unit within which the detention and interrogation program the committee was reviewing was housed. According to Feinstein, he is "mentioned by name more than 1,600 times" in their study.

"And now, this individual is sending a crimes report to the Department of Justice on the actions of congressional staff — the same congressional staff who researched and drafted a report that details how CIA officers, including the acting general counsel himself, provided inaccurate information to the Department of Justice about the program," she said.

Based on Feinstein's description, she seems to be referring to Robert Eatinger, who some sources finger as being involved in destroying video evidence of enhanced interrogation in action.  Feinstein raised the issue of those tapes near the beginning of her speech.

So how did Feinstein react to learning about the investigation? 

Two days after that first January meeting, Feinstein sent a letter to Brennan objecting to any further CIA investigation, citing the constitutional separation of power issues it raised. She wrote again on Jan. 23, asking 12 specific questions about the CIA's actions — including the scope of the investigation and what legal grounds the agency had for pursuing it. To date, she says, the spy agency has refused to answer her inquires.

But, she says, days after her meeting with Brennan, CIA inspector general David Buckley informed her he had referred her concerns about CIA actions toward the committee and its staff to the Department of Justice, "given the possibility of a criminal violation by CIA personnel." As for the CIA's referral of a case concerning the actions of committee staff, Feinstein says she views it as "a potential effort to intimidate" her staff.

For her part, Feinstein has "grave concerns that the CIA's search may well have violated the separation of powers principle embodied in the United States Constitution."

So, uh, what exactly are the constitutional implications? 

Well, the U.S. government is broken up into three branches: The executive, legislative and judicial. They each have their own specific authorities, with checks and balances over the other branches. One of the checks the legislative branch is responsible for is oversight of intelligence activities — hence their investigation into the CIA's detention and interrogation practices. By interfering with its investigation, Feinstein appears to believe the CIA has crossed a line in an attempt to thwart the release of the committee's report. But she also believes the CIA has potentially crossed a slew of other lines.

"Besides the constitutional implications," Feinstein said today, "the CIA search may also have violated the Fourth Amendment, the Computer Fraud and Abuse Act, as well as Executive Order 12333, which prohibits the CIA from conducting domestic searches or surveillance."

What does Brennan have to say about all of this? 

Conveniently, Brennan sat down for a talk with the Council on Foreign Relations almost immediately after Feinstein's speech, and moderator Andrea Mitchell's first question was about Feinstein's allegations. He said "appropriate authorities" both outside and inside the CIA are looking at both agency officer and staff committee activities. 

"I would just encourage members of the Senate to take their time to make sure they don't overstate what they claim and what I'm sure they believe to be the truth," he told Mitchell. Asked if he would resign if Feinstein's allegation were true, he responded: "If I did something wrong, I will go to the president and explain exactly what I did and what the findings were. He is the one who can ask me to stay or to go."