Thread by @KimZetter

We've been hearing a lot about a surveillance gap since SolarWinds hack was exposed. Officials call it a “blind spot,” a "visibility" issue and an authorities “gap." But they've been vague about what they mean by it. Turns out it's not quite what you think zetter.substack.com/p/mind-the-gap…

I spoke w/ former NSA General Counsel Glenn Gerstell about the surveillance gap, and it turns out it's not about not being able to see into US private-sector systems at all, but about FBI not being able to get a warrant quickly enough or get one when there isn't probable cause.

Gerstell described hypothetical: NSA sees data leave US computer and go to one in Europe; then data leaves Europe computer and goes to one in Russia. Suspects it's intel stolen by foreign power but doesn't have evidence for probable cause emergency access to US computer to verify

Gerstell thinks NSA or FBI or other authority should be able to access US computer to determine if foreign power is using it as command center to hack other US computers. But this would bypass protections in the Foreign Intelligence Surveillance Act.

"If the NSA or FBI could quickly examine that U.S. machine, they could determine 'within hours' that the machine is a vector for malicious activity by a foreign power. 'And that would be a big improvement over what is now a several-days process,'" he said.

But for emergency access, FISA requires prob cause that a foreign power/agent of foreign power is involved. But it's not always possible to know without accessing US system first. He thinks NSA/FBI should be able to do warrantless search of that US computer without prob cause

Experts like @granick, @RonWyden and others says prob cause protection in FISA is there for good reason. And @DAlperovitch says there's another reason you don't want to allow this:

What if the U.S. system is not a command-and-control server at all but is part of a presidential campaign's infrastructure, and "suddenly you’re monitoring a presidential campaign [computer]? You don’t want to be in that business,” @DAlperovitch told me.