Interview with Kip Hawley
In April, Kip Hawley, the head of the Transportation Security Administration (TSA), invited me to Washington for a meeting. Despite some serious trepidation, I accepted. And it was a good meeting. Most of it was off the record, but he asked me how the TSA could overcome its negative image. I told him to be more transparent, and stop ducking the hard questions. He said that he wanted to do that. He did enjoy writing a guest blog post for Aviation Daily, but having a blog himself didn't work within the bureaucracy. What else could he do?
This interview, conducted in May and June via e-mail, was one of my suggestions.
Bruce Schneier: By today's rules, I can carry on liquids in quantities of three ounces or less, unless they're in larger bottles. But I can carry on multiple three-ounce bottles. Or a single larger bottle with a non-prescription medicine label, like contact lens fluid. It all has to fit inside a one-quart plastic bag, except for that large bottle of contact lens fluid. And if you confiscate my liquids, you're going to toss them into a large pile right next to the screening station—which you would never do if anyone thought they were actually dangerous.
Can you please convince me there's not an Office for Annoying Air Travelers making this sort of stuff up?
Kip Hawley: Screening ideas are indeed thought up by the Office for Annoying Air Travelers and vetted through the Directorate for Confusion and Complexity, and then we review them to insure that there are sufficient unintended irritating consequences so that the blogosphere is constantly fueled. Imagine for a moment that TSA people are somewhat bright, and motivated to protect the public with the least intrusion into their lives, not to mention travel themselves. How might you engineer backwards from that premise to get to three ounces and a baggie?
We faced a different kind of liquid explosive, one that was engineered to evade then-existing technology and process. Not the old Bojinka formula or other well-understood ones—TSA already trains and tests on those. After August 10, we began testing different variants with the national labs, among others, and engaged with other countries that have sophisticated explosives capabilities to find out what is necessary to reliably bring down a plane.
We started with the premise that we should prohibit only what's needed from a security perspective. Otherwise, we would have stuck with a total liquid ban. But we learned through testing that that no matter what someone brought on, if it was in a small enough container, it wasn't a serious threat. So what would the justification be for prohibiting lip gloss, nasal spray, etc? There was none, other than for our own convenience and the sake of a simple explanation.
Based on the scientific findings and a don't-intrude-unless-needed-for-security philosophy, we came up with a container size that eliminates an assembled bomb (without having to determine what exactly is inside the bottle labeled "shampoo"), limits the total liquid any one person can bring (without requiring Transportation Security Officers (TSOs) to count individual bottles), and allows for additional security measures relating to multiple people mixing a bomb post-checkpoint. Three ounces and a baggie in the bin gives us a way for people to safely bring on limited quantities of liquids, aerosols and gels.
BS: How will this foil a plot, given that there are no consequences to trying? Airplane contraband falls into two broad categories: stuff you get in trouble for trying to smuggle onboard, and stuff that just gets taken away from you. If I'm caught at a security checkpoint with a gun or a bomb, you're going to call the police and really ruin my day. But if I have a large bottle of that liquid explosive, you confiscate it with a smile and let me though. So unless you're 100% perfect in catching this stuff—which you're not—I can just try again and again until I get it through.
This isn't like contaminants in food, where if you remove 90% of the particles, you're 90% safer. None of those false alarms—none of those innocuous liquids taken away from innocent travelers—improve security. We're only safer if you catch the one explosive liquid amongst the millions of containers of water, shampoo, and toothpaste. I have described two ways to get large amounts of liquids onto airplanes—large bottles labeled "saline solution" and trying until the screeners miss the liquid—not to mention combining multiple little bottles of liquid into one big bottle after the security checkpoint.
I want to assume the TSA is both intelligent and motivated to protect us. I'm taking your word for it that there is an actual threat—lots of chemists disagree—but your liquid ban isn't mitigating it. Instead, I have the sinking feeling that you're defending us against a terrorist smart enough to develop his own liquid explosive, yet too stupid to read the rules on TSA's own website.
KH: I think your premise is wrong. There are consequences to coming to an airport with a bomb and having some of the materials taken away at the checkpoint. Putting aside our layers of security for the moment, there are things you can do to get a TSO's attention at the checkpoint. If a TSO finds you or the contents of your bag suspicious, you might get interviewed and/or have your bags more closely examined. If the TSO throws your liquids in the trash, they don't find you a threat.
I often read blog posts about how someone could just take all their three-ounce bottles—or take bottles from others on the plane—and combine them into a larger container to make a bomb. I can't get into the specifics, but our explosives research shows this is not a viable option.
The current system is not the best we'll ever come up with. In the near future, we'll come up with an automated system to take care of liquids, and everyone will be happier.
In the meantime, we have begun using hand-held devices that can recognize threat liquids through factory-sealed containers (we will increase their number through the rest of the year) and we have different test strips that are effective when a bottle is opened. Right now, we're using them on exempt items like medicines, as well as undeclared liquids TSOs find in bags. This will help close the vulnerability and strengthen the deterrent.
BS: People regularly point to security checkpoints missing a knife in their handbag as evidence that security screening isn't working. But that's wrong. Complete effectiveness is not the goal; the checkpoints just have to be effective enough so that the terrorists are worried their plan will be uncovered. But in Denver earlier this year, testers sneaked 90% of weapons through. And other tests aren't much better. Why are these numbers so poor, and why didn't they get better when the TSA took over airport security?
KH: Your first point is dead on and is the key to how we look at security. The stories about 90% failures are wrong or extremely misleading. We do many kinds of effectiveness tests at checkpoints daily. We use them to guide training and decisions on technology and operating procedures. We also do extensive and very sophisticated Red Team testing, and one of their jobs is to observe checkpoints and go back and figure out—based on inside knowledge of what we do—ways to beat the system. They isolate one particular thing: for example, a particular explosive, made and placed in a way that exploits a particular weakness in technology; our procedures; or the way TSOs do things in practice. Then they will test that particular thing over and over until they identify what corrective action is needed. We then change technology or procedure, or plain old focus on execution. And we repeat the process—forever.
So without getting into specifics on the test results, of course there are times that our evaluations can generate high failure rate numbers on specific scenarios. Overall, though, our ability to detect bomb components is vastly improved and it will keep getting better. (Older scores you may have seen may be "feel good" numbers based on old, easy tests. Don't go for the sound-bite; today's TSOs are light-years ahead of even where they were two years ago.)
BS: I hope you're telling the truth; screening is a difficult problem, and it's hard to discount all of those published tests and reports. But a lot of the security around these checkpoints is about perception—we want potential terrorists to think there's a significant chance they won't get through the checkpoints—so you're better off maintaining that the screeners are better than reports indicate, even if they're not.
Backscatter X-ray is another technology that is causing privacy concerns, since it basically allows you to see people naked. Can you explain the benefits of the technology, and what you are doing to protect privacy? Although the machines can distort the images, we know that they can store raw, unfiltered images; the manufacturer Rapiscan is quite proud of the fact. Are the machines you're using routinely storing images? Can they store images at the screener's discretion, or is that capability turned off at installation?
KH: We're still evaluating backscatter and are in the process of running millimeter wave portals right alongside backscatter to compare their effectiveness and the privacy issues. We do not now store images for the test phase (function disabled), and although we haven't officially resolved the issue, I fully understand the privacy argument and don't assume that we will store them if and when they're widely deployed.
BS: When can we keep our shoes on?
KH: Any time after you clear security. Sorry, Bruce, I don't like it either, but this is not just something leftover from 2002. It is a real, current concern. We're looking at shoe scanners and ways of using millimeter wave and/or backscatter to get there, but until the technology catches up to the risk, the shoes have to go in the bin.
BS: This feels so much like "cover your ass" security: you're screening our shoes because everyone knows Richard Reid hid explosives in them, and you'll be raked over the coals if that particular plot ever happens again. But there are literally thousands of possible plots.
So when does it end? The terrorists invented a particular tactic, and you're defending against it. But you're playing a game you can't win. You ban guns and bombs, so the terrorists use box cutters. You ban small blades and knitting needles, and they hide explosives in their shoes. You screen shoes, so they invent a liquid explosive. You restrict liquids, and they're going to do something else. The terrorists are going to look at what you're confiscating, and they're going to design a plot to bypass your security.
That's the real lesson of the liquid bombers. Assuming you're right and the explosive was real, it was an explosive that none of the security measures at the time would have detected. So why play this slow game of whittling down what people can bring onto airplanes? When do you say: "Enough. It's not about the details of the tactic; it's about the broad threat"?
KH: In late 2005, I made a big deal about focusing on Improvised Explosives Devices (IEDs) and not chasing all the things that could be used as weapons. Until the liquids plot this summer, we were defending our decision to let scissors and small tools back on planes and trying to add layers like behavior detection and document checking, so it is ironic that you ask this question—I am in vehement agreement with your premise. We'd rather focus on things that can do catastrophic harm (bombs!) and add layers to get people with hostile intent to highlight themselves. We have a responsibility, though, to address known continued active attack methods like shoes and liquids and, unfortunately, have to use our somewhat clunky process for now.
BS: You don't have a responsibility to screen shoes; you have one to protect air travel from terrorism to the best of your ability. You're picking and choosing. We know the Chechnyan terrorists who downed two Russian planes in 2004 got through security partly because different people carried the explosive and the detonator. Why doesn't this count as a continued, active attack method?
I don't want to even think about how much C4 I can strap to my legs and walk through your magnetometers. Or search the Internet for "BeerBelly." It's a device you can strap to your chest to smuggle beer into stadiums, but you can also use it smuggle 40 ounces of dangerous liquid explosive onto planes. The magnetometer won't detect it. Your secondary screening wandings won't detect it. Why aren't you making us all take our shirts off? Will you have to find a printout of the webpage in some terrorist safe house? Or will someone actually have to try it? If that doesn't bother you, search the Internet for "cell phone gun."
It's "cover your ass" security. If someone tries to blow up a plane with a shoe or a liquid, you'll take a lot of blame for not catching it. But if someone uses any of these other, equally known, attack methods, you'll be blamed less because they're less public.
KH: Dead wrong! Our security strategy assumes an adaptive terrorist, and that looking backwards is not a reliable predictor of the next type of attack. Yes, we screen for shoe bombs and liquids, because it would be stupid not to directly address attack methods that we believe to be active. Overall, we are getting away from trying to predict what the object looks like and looking more for the other markers of a terrorist. (Don't forget, we see two million people a day, so we know what normal looks like.) What he/she does; the way they behave. That way we don't put all our eggs in the basket of catching them in the act. We can't give them free rein to surveil or do dry-runs; we need to put up obstacles for them at every turn. Working backwards, what do you need to do to be successful in an attack? Find the decision points that show the difference between normal action and action needed for an attack. Our odds are better with this approach than by trying to take away methods, annoying object by annoying object. Bruce, as for blame, that's nothing compared to what all of us would carry inside if we failed to prevent an attack.
BS: Let's talk about ID checks. I've called the no-fly list a list of people so dangerous they cannot be allowed to fly under any circumstance, yet so innocent we can't arrest them even under the Patriot Act. Except that's not even true; anyone, no matter how dangerous they are, can fly without an ID—or by using someone else's boarding pass. And the list itself is filled with people who shouldn't be on it—dead people, people in jail, and so on—and primarily catches innocents with similar names. Why are you bothering?
KH: Because it works. We just completed a scrub of every name on the no-fly list and cut it in half—essentially cleaning out people who were no longer an active terror threat. We do not publicize how often the no-fly system stops people you would not want on your flight. Several times a week would low-ball it.
Your point about the no-ID and false boarding pass people is a great one. We are moving people who have tools and training to get at that problem. The bigger issue is that TSA is moving in the direction of security that picks up on behavior versus just keying on what we see in your bag. It really would be security theater if all we did was try to find possible weapons in that crunched fifteen seconds and fifteen feet after you anonymously walk through the magnetometer. We do a better job, with less aggravation of ordinary passengers, if we put people-based layers further ahead in the process—behavior observation based on involuntary, observable muscle behavior, canine teams, document verification, etc.
BS: We'll talk about behavioral profiling later; no fair defending one security measure by pointing to another, completely separate, one. How can you claim ID cards work? Like the liquid ban, all it does is annoy innocent travelers without doing more than inconveniencing any future terrorists. Is it really good enough for you to defend me from terrorists too dumb to Google"print your own boarding pass"?
KH: We are getting at the fake boarding pass and ID issues with our proposal to Congress that would allow us to replace existing document checkers with more highly trained people with tools that would close those gaps. Without effective identity verification, watch lists don't do much, so this is a top priority.
Having highly trained TSOs performing the document checking function closes a security gap, adds another security layer, and pushes TSA's security program out in front of the checkpoint.
BS: Let's move on. Air travelers think you're capricious. Remember in April when the story went around about the Princeton professor being on a no-fly list because he spoke out against President Bush? His claims were easily debunked, but the real story is that so many people believed it. People believe political activity puts them on the list. People are afraid to complain about being mistreated at checkpoints because they're afraid it puts them on a list. Is there anything you can do to make this process more transparent?
KH: We need some help on this one. This is the biggest public pain point, dwarfing shoes and baggies.
First off, TSA does not add people to the watch-lists, no matter how cranky you are at a checkpoint. Second, political views have nothing to do with no-flys or selectees. These myths have taken on urban legend status. There are very strict criteria and they are reviewed by lots of separate people in separate agencies: it is for live terror concerns only. The problem comes from random selectees (literally mathematically random) or people who have the same name and birth date as real no-flys. If you can get a boarding pass, you are not on the no-fly list. This problem will go away when Secure Flight starts in 2008, but we can't seem to shake the false impression that ordinary Americans get put on a "list." I am open for suggestions on how to make the public "get it."
BS: It's hard to believe that there could be hundreds of thousands of people meeting those very strict criteria, and that's after the list was cut in half! I know the TSA does not control the no-fly and watch lists, but you're the public face of those lists. You're the aspect of homeland security that people come into direct contact with. Some people might find out they're on the list by being arrested, or being shipped off to Syria for torture, but most people find out they're on the list by being repeatedly searched and questioned for hours at airports.
The main problem with the list is that it's secret. Who is on the list is secret. Why someone's on is secret. How someone can get off is secret. There's no accountability and there's no transparency. Of course this kind of thing induces paranoia. It's the sort of thing you read about in history books about East Germany and other police states.
The best thing you can do to improve the problem is redress. People need the ability to see the evidence against them, challenge their accuser, and have a hearing in a neutral court. If they're guilty of something, arrest them. And if they're innocent, stop harassing them. It's basic liberty.
I don't actually expect you to fix this; the problem is larger than the TSA. But can you tell us something about redress? It's been promised to us for years now.
KH: Redress issues are divided into two categories: people on the no-fly list and people who have names similar to them.
In our experience, the first group is not a heavy user of the redress process. They typically don't want anything to do with the U.S. government. Still, if someone is either wrongly put on or kept on, the Terrorist Screening Center (TSC) removes him or her immediately. In fact, TSA worked with the TSC to review every name, and that review cut the no-fly list in half. Having said that, once someone is really on the no-fly list, I totally agree with what you said about appeal rights. This is true across the board, not just with no-flys. DHS has recently consolidated redress for all DHS activities into one process called DHS TRIP. If you are mistaken for a real no-fly, you can let TSA know and we provide your information to the airlines, who right now are responsible for identifying no-flys trying to fly. Each airline uses its own system, so some can get you cleared to use kiosks, while others still require a visit to the ticket agent. When Secure Flight is operating, we'll take that in-house at TSA and the problem should go away.
BS: I still don't see how that will work, as long as the TSA doesn't have control over who gets on or off the list.
What about Registered Traveler? When TSA first started talking about the program, the plan was to divide people into two categories: more trusted people who get less screening, and less trusted people who get more screening. This opened an enormous security hole; whenever you create an easy way and a hard way through security, you invite the bad guys to take the easier way. Since then, it's transformed into a way for people to pay for better screening equipment and faster processing—a great idea with no security downsides. Given that, why bother with the background checks at all? What else is it besides a way for a potential terrorist to spend $60 and find out if the government is on to them?
KH: Registered Traveler (RT) is a promising program but suffers from unrealistic expectations. The idea—that you and I aren't really risks and we should be screened less so that TSA can apply scarce resources on the more likely terrorist—makes sense and got branded as RT. The problem is that with two million people a day, how can we tell them apart in an effective way? We know terrorists use people who are not on watch lists and who don't have criminal convictions, so we can't use those criteria alone. Right now, I've said that RT is behind Secure Flight in priority and that TSA is open to working with private sector entities to facilitate RT, but we will not fund it, reduce overall security, or inconvenience regular travelers. As private companies deploy extra security above what TSA does, we can change the screening process accordingly. It has to be more than a front-of-the-line pass, and I think there are some innovations coming out in the year ahead that will better define what RT can become.
BS: Let's talk about behavioral profiling. I've long thought that most of airline security could be ditched in favor of well-trained guards, both in and out of uniform, wandering the crowds looking for suspicious behavior. Can you talk about some of the things you're doing along those lines, and especially ways to prevent this from turning into just another form of racial profiling?
KH: Moving security out from behind the checkpoint is a big priority for us. First, it gives us the opportunity to pick up a threat a lot earlier. Taking away weapons or explosives at the checkpoint is stopping the plot at nearly the last possible moment. Obviously, a good security system aims at stopping attacks well before that. That's why we have many layers of security (intel, law enforcement, behavior detection, etc.) to get to that person well before the security checkpoint. When a threat gets to the checkpoint, we're operating on his/her terms—they pick when, where, and how they present themselves to us. We want to pick up the cues on our terms, before they're ready, even if they're just at the surveillance stage.
We use a system of behavior observation that is based on the science that demonstrates that there are certain involuntary, subconscious actions that can betray a person's hostile intent. For instance, there are tiny—but noticeable to the trained person—movements in a person's facial muscles when they have certain emotions. It is very different from the stress we all show when we're anxious about missing the flight due to, say, a long security line. This is true across race, gender, age, ethnicity, etc. It is our way of not falling into the trap where we predict what a terrorist is going to look like. We know they use people who "look like" terrorists, but they also use people who do not, perhaps thinking that we cue only off of what the 9/11 hijackers looked like.
Our Behavior Detection teams routinely—and quietly—identify problem people just through observable behavior cues. More than 150 people have been identified by our teams, turned over to law enforcement, and subsequently arrested. This layer is invisible to the public, but don't discount it, because it may be the most effective. We publicize non-terrorist-related successes like a murder suspect caught in Minneapolis and a bank robber caught in Philadelphia.
Most common are people showing phony documents, but we have even picked out undercover operatives—including our own. One individual, identified by a TSO in late May and not allowed to fly, was killed in a police shoot-out five days later. Additionally, several individuals have been of interest from the counter-terrorism perspective. With just this limited deployment of Behavior Detection Officers (BDOs), we have identified more people of counterterrorism interest than all the people combined caught with prohibited items. Look for us to continue to look at ways that highlight problem people rather than just problem objects.
BS: That's really good news, and I think it's the most promising new security measure you've got. Although, honestly, bragging about capturing a guy for wearing a fake military uniform just makes you look silly.
So far, we've only talked about passengers. What about airport workers? Nearly one million workers move in and out of airports every day without ever being screened. The JFK plot, as laughably unrealistic as it was, highlighted the security risks of airport workers. As with any security problem, we need to secure the weak links, rather than make already strong links stronger. What about airport employees, delivery vehicles, and so on?
KH: I totally agree with your point about a strong base level of security everywhere and not creating large gaps by over-focusing on one area. This is especially true with airport employees. We do background checks on all airport employees who have access to the sterile area. These employees are in the same places doing the same jobs day after day, so when someone does something out of the ordinary, it immediately stands out. They serve as an additional set of eyes and ears throughout the airport.
Even so, we should do more on airport employees and my House testimony of April 19 gives details of where we're heading. The main point is that everything you need for an attack is already inside the perimeter of an airport. For example, why take lighters from people who work with blowtorches in facilities with millions of gallons of jet fuel?
You could perhaps feel better by setting up employee checkpoints at entry points, but you'd hassle a lot of people at great cost with minimal additional benefit, and a smart, patient terrorist could find a way to beat you. Today's random, unpredictable screenings that can and do occur everywhere, all the time (including delivery vehicles, etc.) are harder to defeat. With the latter, you make it impossible to engineer an attack; with the former, you give the blueprint for exactly that.
BS: There's another reason to screen pilots and flight attendants: they go through the same security lines as passengers. People have to remember that it's not pilots being screened, it's people dressed as pilots. You either have to implement a system to verify that people dressed as pilots are actual pilots, or just screen everybody. The latter choice is far easier.
I want to ask you about general philosophy. Basically, there are three broad ways of defending airplanes: preventing bad people from getting on them (ID checks), preventing bad objects from getting on them (passenger screening, baggage screening), and preventing bad things from happening on them (reinforcing the cockpit door, sky marshals). The first one seems to be a complete failure, the second one is spotty at best. I've always been a fan of the third. Any future developments in that area?
KH: You are too eager to discount the first—stopping bad people from getting on planes. That is the most effective! Don't forget about all the intel work done partnering with other countries to stop plots before they get here (UK liquids, NY subway), all the work done to keep them out either through no-flys (at least several times a month) or by Customs & Border Protection on their way in, and law enforcement once they are here (Ft. Dix). Then, you add the behavior observation (both uniformed and not) and identity validation (as we take that on) and that's all before they get to the checkpoint.
The screening-for-things part, we've discussed, so I'll jump to in-air measures. Reinforced, locked cockpit doors and air marshals are indeed huge upgrades since 9/11. Along the same lines, you have to consider the role of the engaged flight crew and passengers—they are quick to give a heads-up about suspicious behavior and they can, and do, take decisive action when threatened. Also, there are thousands of flights covered by pilots who are qualified as law enforcement and are armed, as well as the agents from other government entities like the Secret Service and FBI who provide coverage as well. There is also a fair amount of communications with the flight deck during flights if anything comes up en route—either in the aircraft or if we get information that would be of interest to them. That allows "quiet" diversions or other preventive measures. Training is, of course, important too. Pilots need to know what to do in the event of a missile sighting or other event, and need to know what we are going to do in different situations. Other things coming: better air-to-ground communications for air marshals and flight information, including, possibly, video.
So, when you boil it down, keeping the bomb off the plane is the number one priority. A terrorist has to know that once that door closes, he or she is locked into a confined space with dozens, if not hundreds, of zero-tolerance people, some of whom may be armed with firearms, not to mention the memory of United Flight 93.
BS: I've read repeated calls to privatize airport security: to return it to the way it was pre-9/11. Personally, I think it's a bad idea, but I'd like your opinion on the question. And regardless of what you think should happen, do you think it will happen?
KH: From an operational security point of view, I think it works both ways. So it is not a strategic issue for me.
SFO, our largest private airport, has excellent security and is on a par with its federalized counterparts (in fact, I am on a flight from there as I write this). One current federalized advantage is that we can surge resources around the system with no notice; essentially, the ability to move from anywhere to anywhere and mix TSOs with federal air marshals in different force packages. We would need to be sure we don't lose that interchangeability if we were to expand privatized screening.
I don't see a major security or economic driver that would push us to large-scale privatization. Economically, the current cost-plus model makes it a better deal for the government in smaller airports than in bigger. So, maybe more small airports will privatize. If Congress requires collective bargaining for our TSOs, that will impose an additional overhead cost of about $500 million, which would shift the economic balance significantly toward privatized screening. But unless that happens, I don't see major change in this area.
BS: Last question. I regularly criticize overly specific security measures, because forcing the terrorists to make minor modifications in their tactics doesn't make us any safer. We've talked about specific airline threats, but what about airplanes as a specific threat? On the one hand, if we secure our airlines and the terrorists all decide instead to bomb shopping malls, we haven't improved our security very much. On the other hand, airplanes make particularly attractive targets for several reasons. One, they're considered national symbols. Two, they're a common and important travel vehicle, and are deeply embedded throughout our economy. Three, they travel to distant places where the terrorists are. And four, the failure mode is severe: a small bomb drops the plane out of the sky and kills everyone. I don't expect you to give back any of your budget, but when do we have "enough" airplane security as compared with the rest of our nation's infrastructure?
KH: Airplanes are a high-profile target for terrorists for all the reasons you cited. The reason we have the focus we do on aviation is because of the effect the airline system has on our country, both economically and psychologically. We do considerable work (through grants and voluntary agreements) to ensure the safety of surface transportation, but it's less visible to the public because people other than ones in TSA uniforms are taking care of that responsibility.
We look at the aviation system as one component in a much larger network that also includes freight rail, mass transit, highways, etc. And that's just in the U.S. Then you add the world's transportation sectors—it's all about the network.
The only components that require specific security measures are the critical points of failure—and they have to be protected at virtually any cost. It doesn't matter which individual part of the network is attacked—what matters is that the network as a whole is resilient enough to operate even with losing one or more components.
The network approach allows various transportation modes to benefit from our layers of security. Take our first layer: intel. It is fundamental to our security program to catch terrorists long before they get to their target, and even better if we catch them before they get into our country. Our intel operation works closely with other international and domestic agencies, and that information and analysis benefits all transportation modes.
Dogs have proven very successful at detecting explosives. They work in airports and they work in mass transit venues as well. As we test and pilot technologies like millimeter wave in airports, we assess their viability in other transportation modes, and vice versa.
To get back to your question, we're not at the point where we can say "enough" for aviation security. But we're also aware of the attractiveness of other modes and continue to use the network to share resources and lessons learned.
BS: Thank you very much for your time. I appreciate both your time and your candor.
KH: I enjoyed the exchange and appreciated your insights. Thanks for the opportunity.