While the National Security Agency (NSA) has largely escaped the government shutdown, the panel investigating NSA spying practices has effectively been frozen. Politico reports that as of Friday, the five-member Review Group on Intelligence and Communications Technologies lost its staff to the furlough associated with the government shutdown.

The group, which is largely comprised of intelligence community and White House insiders, was initially scheduled to remain running during the furlough. However, former acting CIA director Michael Morell declined to attend a scheduled meeting Tuesday, citing the shutdown: “While the work we're doing is important, it is no more important than — and quite frankly a lot less important — than a lot of the work being left undone by the government shutdown, both in the intelligence community and outside the intelligence community.”

By Friday, the office of Director of National Intelligence James Clapper, which is facilitating the panel, reversed course and determined that panel members' staff should be furloughed, according to Politico's sources. While in theory the members are unpaid, so the panel could continue without support staff or payment for travel expenses, that seems unlikely.

Clapper was among those warning about possible gaps in national security due to furloughs during a Senate Judiciary Hearing last week. At that point, despite an exception for "national security," Clapper claimed that 70 percent of civilian intelligence workers were furloughed because they weren't deemed to be addressing imminent threats to life or property.

Gen. Keith B. Alexander, NSA's director, echoed his concerns at the hearing, and gave some figures specific to the NSA: “We have over 960 PhDs, over 4,000 computer scientists, over a thousand mathematicians. They are furloughed." By that estimate, around 6,000 NSA employees have been sent home with letters like this one, although the actual total is classified.

We also don't actually know how many people the NSA employs — that information is classified, too. But we do have a pretty good ballpark figure thanks to a 2012 60th anniversary book saying that the number is more than 30,000; a 2012 joke about the range being "somewhere between 37,000 and one billion" from deputy Director Chris Inglis; and a 2013 Der Spiegel report of 40,000 that may have relied on documents from former NSA contractor Edward Snowden. We're going to rely on the Der Spiegel number since it is the most recent, so that means roughly 15 percent of the NSA has been furloughed.

Substantial? Sure. But nowhere near the 97 percent of NASA employees or the 94 percent of EPA employees furloughed. And over the weekend, the NSA's parent agency, the Department of Defense, announced that it was recalling some 90 percent of civilian employees affected by the furlough. So it's entirely possible most of that 15 percent are back on the job now, although the NSA and DoD did not respond to Washington Post inquiries about their current shutdown status.

So while it appears that the NSA will remain largely functional during the shutdown, the inquiry into the agency's spying activities will not.