The $80 billion U.S. intelligence community is a notoriously hard target for the congressional committees charged with overseeing them. Because the programs they check are shrouded in state secrecy, Congress rarely comprehensively digs into the U.S. government’s human espionage, cyber snooping, satellite imagery and wiretapping.

That may be changing. In April, the Senate Select Committee on Intelligence assigned staff to a review of all U.S. intelligence programs, according to staffers on the committee. The staffers have already sent information requests to U.S. spy agencies and they expect to complete the review by next September, according to these staffers.

One senior staff member on the committee said the review intends to develop a “comprehensive list of all the collection programs from the U.S. intelligence community.”

If the committee turns up programs its members were unaware of—and issues a public report of its findings (two big ifs for now)—it could be another vindication for Edward Snowden, the former NSA contractor who leaked a trove of secret documents in 2013.

Already Snowden’s leaks have prompted the Obama administration to conduct its own review of the government’s collection of telephone call records. Obama this year agreed in principle to end the government’s bulk storage of those call records and internal reforms to the process of spying on foreign leaders.

Steven Aftergood, the director on the Project on Government Secrecy at the Federation of American Scientists, said he was unaware of a congressional committee ever conducting a review this broad in scope before. “Most continuing programs escape review during the annual budget cycle,” Aftergood said, referring to the intelligence committee’s role in reviewing the annual $80 billion intelligence community budget. Aftergood added, “Probably the majority of what the intelligence community does gets overlooked, not overseen. That is because the committee needs to pick its targets, so it naturally focuses on what is new and different.”

The continuing programs that would be reviewed, according to committee staff members, would cover the whole range of intelligence collection. “We are talking a very broad scope here,” one senior committee staff member said. “All the programs through which the intelligence community collects intelligence. Human intelligence, signal intelligence, open source. It is all subject to the review.”

The review represents a turnaround for the chairmen and vice chairmen of the intelligence committees, who were particularly critical of Snowden when his first leaks emerged in 2013. Sen. Dianne Feinstein, the Democratic chair of the Senate Select Committee on Intelligence, said on June 10, 2013 that Snowden’s actions amounted to treason, a crime punishable by death.

But as more disclosures came to light, Feinstein began to change her tone at times. Last October, when the international media began reporting on leaked Snowden documents that showed the U.S. government was targeting the personal communications of European leaders like Chancelor Angela Merkel of Germany, Feinstein was outraged.

On October 28 of last year, Feinstein issued a statement saying a “total review of all intelligence programs” was necessary. “It is clear to me that certain surveillance activities have been in effect for more than a decade and that the Senate Intelligence Committee was not satisfactorily informed. Therefore our oversight needs to be strengthened and increased,” she said.

Feinstein’s statement was the genesis of the committee’s new review of intelligence programs, though the staff did not begin the work until April of this year.

The process for informing the Senate and House intelligence committees is often shrouded in secrecy. The most detailed and comprehensive briefings are often limited to the chairman and ranking members of the committees.

A senior staff member on the committee said one of the purposes of the study would be to find out about intelligence collection activities that may have been kept from the committee. “If there are intelligence collection programs we don’t know about, that’s something we’d want to know about,” this staff member said. What’s more, the review, according to this staffer, was meant to assure the committee that the intelligence collection activities were “lawfully executed,” and to weed out duplicative intelligence activities.

The work of the review is expected to be finished by next September. But it’s still not clear whether a version of the final report will be made public. Intelligence Committee staff members say there has been no determination yet as to whether there will be an unclassified version of the final report.

If the report remains classified, it will be different from one of Feinstein’s top priorities this year for her oversight committee. The senator and her staff are currently pressing the White House to disclose more information in a public version of a majority staff report cataloguing the history of the CIA’s black site detention and interrogation program. That report was supposed to be published this summer, but its release to the public has been delayed over negotiations over what information—like the names of detainees and the countries hosting secret prisons—should be redacted from the final product.

If Republicans win control of the Senate in November, the man who will be making that call is likely to be Sen. Richard Burr, the Republican next in line for the chairmanship of the intelligence committee.

When Feinstein first accused the CIA of spying on her own staffers during their investigation of the agency’s network of secret prisons during the last administration, Burr did not join other Republicans like Sen. Lindsey Graham in condemning the Obama administration. Instead, he told reporters at the time he didn’t “believe that anything that goes on in the intelligence committee should ever be discussed publicly.”

At the time CIA director John Brennan denied the CIA had done anything wrong. In July, he apologized.