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Backscatter X-Ray Machines Easily Fooled
Pinckney writes "A paper by Leon Kaufman and Joseph W. Carlson in the Journal of Transportation Security asserts that x-ray backscatter machines are not very effective (PDF) even in their intended role. While carelessly placed contraband will be detected, the machines have glaring blind-spots and have difficulty distinguishing explosives from human tissue. As they write, 'It is very likely that a large (15–20 cm in diameter), irregularly-shaped, cm-thick pancake [of PETN explosive] with beveled edges, taped to the abdomen, would be invisible to this technology. ... It is also easy to see that an object such as a wire or a boxcutter blade, taped to the side of the body, or even a small gun in the same location, will be invisible.'"
This obviously means that we are going to need better technology. We'll need technology that will be able to give us a full color representation of your completely nude body, but only if you're a hot chick. - Your Friendly local TSA Agent
It's highly questionable whether the machines are even capable of identifying "suspicious areas of the image." But suppose for a moment that they are. These scanners are already, in themselves, more of a safety hazard than actually flying. They have been through nowhere near the degree of rigorous safety testing and analysis that any component of an aircraft has to go through. While exposure to the intended dose of radiation for a scan may be safe (even that is debatable), the scanning process is software controlled. Imagine if the software crashes in the middle of a scan, or the scanner mechanism sticks.
And now, suppose that it is possible to detect suspicious areas of an image and do a more thorough scan. This simply increases the safety risks of these machines. X-ray scanners? How is that exposure going to be controlled? Is testing ever going to be held to the degree of rigor required for aircraft? If not, why should we be willing to accept the risks of using these machines?
The fact is that if we really care about people taping explosives to their stomachs, the only way to detect this is with a thorough search (a.k.a. "enhanced patdown"). If we are really that concerned about security, that is what every traveler should be subject to. And if we aren't comfortable with searching passengers like that, then we really ought to stop being such cowards and accept the quite minimal risk that someone is going to get one of these Rube Goldberg explosive devices past security and actually succeed in harming an aircraft with it (unlike the shoe-bomber and underwear bomber attempts, which did not harm either aircraft).
Why didn't the TSA test this technology first to make sure it works? I mean, it's not like cloth tape and a flattened explosive are unprecedented or amazingly cunning bits of circumvention! Why not hire 20 nerds and give them a week to figure out if they can sneak something truly dangerous through the scanner? As long as they can do so reliably, wait for the next version of the machine and test again. Only when it works should you place the order!
Thing is, we don't even really need "a better way of detecting terrorists". The incidence of terrorism against airlines is practically a rounding error and as we've seen, the TSA has been unsuccessful in preventing the (very few) attempted bombings in the recent past yet the attacks still failed. If we removed the theatre and replaced it with nothing, maybe keeping a few basic and effective measures to discourage obvious attacks, we'd be better off, and the risk would still be negligible. If we replaced it with something actually effective then that'd theoretically be even better, but most effective methods are expensive, invasive or both and I'm unconvinced that they would be worthwhile considering how low the risk is.
The Boston Globe reported today that a the mutilated body of a teen boy found last month in a Boston suburb probably fell out of the wheel well of an airplane he is believed to stowed away on. Several articles of his clothing were found scattered along the flight's approach to Boston's Logan Airport.
Earlier this year in Japan a body was discovered in the wheel well of a flight originating at New York's JFK. Investigation later revealed that the unfortunate hadn't stowed away in New York, but in Lagos Nigeria *two months earlier*.
What does this tell you about all this body scanning hoopla? We're building a fortress that sports a fearsome looking portcullis but has open windows on the ground floor.
Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.
Not to sound like a [ Buffering.... ]
meep
Precisely. The shoe bomber got through, and his bomb didn't work. Ditto the underpants bomber. Airport security failed miserably. It didn't matter.
As for the liquid bombers, it's still debatable whether their bomb would have worked, but who cares? They never even made it as far as the airport!
I am still waiting for the TSA to present the American people with any evidence -- even the tiniest shred of evidence -- that they have ever once in their entire history caught an actual terrorist.
>not very effective (PDF) even in their intended role
You're implicitly buying in to the claim that their intended role has something to do with safety.
The purpose of a system is what it does. The ~$200,000 scanner purchases funnel tax money to a company which made payments to the former director of Homeland Security. They condition people to being treated like prisoners. The first was deliberate.
They're working perfectly.
"These scanners are already, in themselves, more of a safety hazard than actually flying. They have been through nowhere near the degree of rigorous safety testing and analysis that any component of an aircraft has to go through."
Consider the level of testing and analysis that the *very same device* would require if it were labeled "medical equipment" rather than "airport security equipment". Consider also the site and personnel licensing required to operate one (probably akin to that required for a modern xray machine).
~REZ~ #43301. Who'd fake being me anyway?
You might have gone through radiotherapy, but these machines work on different frequencies and different energy levels. Yes, the wave energies might not be as high as in radiotherapy, but that doesn't make it less dangerous, it actually means that the skin gets the dosage instead of the body.
The dosage you have received over the course of your treatment was carefully measured and calibrated often. It was also administered by a person trained in radiography and the repercussions of radiation.
Also, remember that the dose applied in the scan is done over a relatively short period. For the sake of an analogy, think of the difference in pressure between a stilletto heel and a boot heel on your foot. One will hurt, the other will go right through you.
Compare the mass of your skin to that of your body, add in that you're getting a dose like that in a short time and then come back to me when you realise that it is actually a very serious health concern.
Yes, IANaRP (nuclear and radiation physicist). Posted anon, because I'd like to keep my job.
Behavioral profiling, such as what is practiced by the Israelis, is both cheaper and more effective than searching for weapons. If we adopted behavioral profiling, screened all baggage for explosives and ran passengers through the air-puff chemical sensors we'd have a system that protects travelers privacy much better, is much more effective and significantly cheaper than our current system.
Explosives are the real threat anymore. A few terrorists wonldn't be able to take over an airplane, not now that the passengers will fight back and the cockpit doors are reinforced. Preventing passengers from bringing things like nail clippers is just asinine.