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What's the Big Secret?

the breakfast table
entries
12345678910
from: Orin Kerr
to: Patrick Radden Keefe, David Kris, and Marty Lederman

It's All About the Filters

Posted Wednesday, Aug. 29, 2007, at 12:36 PM ET

Marty, Patrick, David,

Let's play a game, a game I call "guess the classified program." Here's how it will work. I'll imagine a secret government program, but I won't tell you anything about it. I'll hand you a poorly written, decades-old statute and then leak a few hints about it through the Times.

Then, you guys have to guess exactly what the program is and how it works.

Whoever wins that game will go on to the bonus round. Now I'll give you another 16 pages of legalese called the "Protect America Act." Your task: Tell me exactly how the new law changes the secret program.

Ready to play?

Oh, wait, that's the game we're already playing.

So, here's my guess: I think it's all about the filters. Let me explain. Back in the 1970s, as David explains, almost all foreign calls were made by bouncing the calls off satellites. The NSA put up listening stations around the world, and those listening stations scooped up all the foreign calls it could from the air and sent them back to the NSA.

When Congress passed FISA in 1978, Congress mostly stayed away and let the NSA do its thing. The monitoring was occurring abroad and was targeting people outside the United States, so Congress didn't much care.

FISA is in the headlines today because those old dividing lines no longer work. Today communications are traveling over fiber-optic lines, and there's no longer a clear connection between the location of the people monitored and the location of their communications. As David says, all the traffic is mixed together. Grandma's e-mail to cousin Thelma in Omaha, Neb., is carried over the same line as communications among al-Qaida trainees in the mountains of Pakistan. Finding a foreign-to-foreign call or e-mail requires dipping into a stream of traffic and filtering out the calls that are between foreigners.

The real debate is about those filter settings. It's about how filters are set both when the government has no warrant and when it does. In a perfect world, we would have perfect filters. They would identify and sort all of the conversations that fit into different legal boxes, like foreign-to-foreign or foreign-to-domestic. Heck, in a perfect world, we could just monitor the bad guys and never watch the good guys. But we don't live in a perfect world, and the question is how to set those filters to match up with the nice boxes of the law.

As far as I can tell, the secret FISA court decisions and the Protect America Act that it triggered involve different approaches to how to set the filter. We know that the different judges on the FISA court split on the legality of the government's initial plan. In all likelihood, they disagreed on whether the plan was using lawful filter settings. The law allows the government to monitor foreign-to-foreign communications without a warrant. One judge thought the government's filter setting would do that. Another disagreed.

The Protect America Act solves the problem—at least from the government's perspective—by saying that "reasonable" filter settings are good enough. The intelligence folks work with particular targets in mind: They identify individual bad guys and try to watch them. Under the new law, the government can, without a warrant, set its filter to capture the communications of those targets "reasonably believed" to be outside the United States. It can then ask the FISA judges to check out the new filter settings. So long as the filter settings aren't a really wacky way to try to identify foreign communications, the judges have to go along and approve the program.

Is this a good idea or a bad one? I think it depends on the filter settings. Maybe the NSA has figured out settings that accurately identify foreign traffic. Maybe its settings can identify traffic to or from particular cities or regions, or can otherwise identify traffic likely to be of interest. We don't know, as the filter settings are classified. And with good reason, too: Announcing the filter setting tells the world how to sneak through. But without knowing the setting, it's hard for to know how the law is going to work.

Marty, you speculate that the government is breaking this down into two stages. A first computer uses a wide initial filter to identify foreign calls. Next, a second computer filters through that database for suspicious calls and e-mails that might contain terrorist communications. If you're right, wouldn't the desirability of the program hinge on those filter settings? Imagine the filters at both stage are perfect. The data-mining passes on only calls and e-mails involving terrorists discussing their plans. Wouldn't that be pretty much ideal? It seems to me that we get uncomfortable only when the filter settings are lousy. The worse the filter, the more innocent people are being watched. So, again, can we really evaluate the program without knowing the filter and how accurate it is?

David raises a really cool constitutional question: How can the government filter through all that traffic and still make the search "reasonable" under the Fourth Amendment? It can because the filter setting determines the legality of the screening. For example, if the filter is set so that it doesn't collect any contents of communications, it wouldn't be a Fourth Amendment search at all. That's what the 9th Circuit held recently in United States v. Forrester: Monitoring at an ISP that collects only noncontent information doesn't trigger Fourth Amendment protection.

The same idea applies when the government targets content. The issue is how the filter is set and what the monitoring collects. This came up in United States v. Scarfo, a New Jersey case from 2001. In that case, the government obtained a warrant and installed a keystroke-monitoring device on the computer of a New Jersey Mafia boss, Little Nicky Scarfo. The monitoring revealed the boss's encryption pass phrase, letting the government decrypt his private files and use the evidence against him. Scarfo argued that the warrant was an illegal general warrant because it let the government screen every single keystroke he typed.

But the judge disagreed with Little Nicky. He ruled that the legality of the monitoring depended on what the government was looking for, rather than what information passed through the filter. The same idea applies to monitoring over communications networks. So long as the filter setting is reasonable, the search should be reasonable.

As I said, it's all about the filters.

Orin

the breakfast table
entries
12345678910
from: Orin Kerr
to: Patrick Radden Keefe, David Kris, and Marty Lederman

It's All About the Filters

Posted Wednesday, Aug. 29, 2007, at 12:36 PM ET
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Patrick Radden Keefe, a fellow at the Century Foundation, is the author of Chatter, which is out in paperback. Orin Kerr is a law professor at George Washington University and blogs at the Volokh Conspiracy. As associate deputy attorney general from 2000 to 2003, David Kris supervised the government's use of the Foreign Intelligence Surveillance Act, represented the Justice
Department at the National Security Council, and assisted the attorney general in conducting oversight of the U.S. intelligence community. Marty Lederman teaches constitutional law at the Georgetown University Law Center and is a frequent contributor to Balkinization and SCOTUSblog
Entry 1: Photograph of Mike McConnell by Jim Watson/Agence France-Presse/Getty Images. Entry 6: Photograph of NSA headquarters in Fort Meade, Md., by NSA via Getty Images.
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Remarks from the Fray:

How quickly we forget, it seems, that the executive, legislative, and executive are all part of the 'government.' What we have here is an argument not about what the government can and can't do, but who in the government can do it. Various people favor various branches, in large part, it seems, because they believe that certain branches share biases they trust and others share biases they don't trust.

All in all, though, a sensible person could question the independence of a bunch of ex-lawyers (judges) and a bunch of ex-lawyers (legislators) - in fact, it is mostly the executive where some variety enters into it; whether we trust them or not is yet another story. In the end, you'd think that judges, cops and lawmakers tend to be in the same camp vis a vis the freedoms of the people.

So, why bother with all this judicial review? Basically to involve more people and slow things down. But do we really want to just gum up the works in fighting terrorism, with the hope that a less powerful government will treat us better? Frankly, if we want a less powerful government, we should probably cut all sorts of mandates, privileges, and so on - eliminate state charity, subsidies, federal regulation of intrastate commerce, etc - and leave the NSA and CIA to do their work fighting terrorism, at least for the moment. The long arm of government into our personal lives starts with the pocketbook, health care, taxes, etc and ends with law enforcement, not the other way around.

--BenK

(To reply, click here.)

Imagine that the government is clever enough that it can come up with a filter that has a 99.99% chance of tagging a non-terrorist communication as non-terrorist, and a 99.99% chance of tagging a terrorist-related communication as terrorist. I think we'd all be impressed. Further guess that as many as 1 out of 10,000 (0.01%) of all the communications under surveillance are terrorist-related.

If you do the math, out of 100,000,000 communications, you'll have 10,000 genuine terrorist communications, 9999 of which you'll correctly tag as terrorist (the other one will slip through the cracks). Of the 99,990,000 non-terrorist communications, you'll correctly tag 99,980,001 of them as non-terrorist, leaving 9999 as false positives. So because terrorist communications are rare, even this very good filter will produce a false positive for every true positive.

And if that 1 out of 10,000 calls is in fact an overestimate, the number of false positives will outnumber the true positives. If only 1 out of 100,000 calls were terrorist-related, then the false positives would outnumber the true positives by about 10 to 1.

And that's ignoring the manpower issue of who's going to drill down into those 19,998 communications tagged as terrorist by the filter, half of which will be a frustrating waste of time.

--StatNerd

(To reply, click here.)

David Kriss says that there is widespread agreement that it is okay for the U.S. government to intercept "foreign-to-foreign" communications without any oversight or accountability. Why is it that Americans, even those who are strong advocates for the right to privacy, can dismiss the privacy expectations of non-Americans without a thought?

Not all foreigners are terrorists hiding out in mountain caverns. Canada is your nearest neighbour, largest trading partner, and a strong friend and ally. When your government closed all U.S. airports on September 11, hundreds of aircraft were diverted to Canada. At the time, no-one knew that there were only four planes involved in the attack, and for all we knew we could have been putting ourselves in harm's way. The authorities in Canada agreed to admit these aircraft into our airspace anyway, and hundreds of Canadian families took stranded American travellers into their homes. Our soldiers have been fighting in Afghanistan since shortly after the invasion, and are suffering casualties at a higher rate than any other forces, including your own.

The NSA has the capacity to monitor the communications of our security services, government officials, businesses, and private individuals. The U.S. Congress has given them free reign to do so, and there is "widespread agreement", among Americans anyway, that this is "appropriate". Why?

--ovation

(To reply, click here.)

What you're doing is a legal analysis of how these programs comport with the jurisprudence and legislation of the past (FISA) and also more recent legislation. This analysis occurs in a relative vacuum.'

It's my understanding that during WWII our security agencies took substantial latitude with privacy protections. If so, were these legal then given wartime conditions? Or was there legislation, since rescinded, that legalized these actions? Or would subsequent jurisprudence make these actions questionable?

Rights cannot be absolute but must be the result of a weighing of threat vs the value of privacy. It would seem obvious that in wartime this balance shifts. Obviously this isn't WWII. But its also not the Cold War. In fact its easy to argue, from a homeland security point of view this situation is more dire than either WWII or the Cold War. Our opponents are indelibly organized to try to kill us in large numbers!!!! They already have.

Then we had other means, more appropriate to the circumstances (armies, planes) to protect us. Now surveillance has gone from a useful auxiliary activity to a primary weapon. So the balance of threat vs. privacy rationally must shift against privacy.

To do so requires action, some of it secret, necessarily on the part of the executive. Such considerations seemingly play no part in your analysis, yet they seem to me to be critical. Obviously in such circumstances we end up relying on the discretion of the executive more than we're used to. Yes there is a greater potential for abuse. But there is a check still.

If discretion is abused in a functional sense that hurts innocent people there will be victims with a cause of action. So far the surveillance programs seem to be victimless "crimes". Or maybe the administration is in fact being reasonable with the program.

--Breaker

(To reply, click here.)

(9/2)

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