from the be-real dept
The images are very sensitive to the presence of large pieces of high Z material, e. g., iron, but unless the spatial resolution is good, thin wires will be missed because of partial volume effects. It is also easy to see that an object such as a wire or a box- cutter blade, taped to the side of the body, or even a small gun in the same location, will be invisible. While there are technical means to mildly increase the conspicuity of a thick object in air, they are ineffective for thin objects such as blades when they are aligned close to the beam direction.In other words, strap a knife to your side, and perhaps the machine won't spot it. We heard that years ago. So, nothing new here.
Plus, I'm pretty sure that the machines now take images from multiple angles, which would rule out this vulnerability. On top of that, Corbett bases his claim on a couple of sample images that are black and white -- and uses that to claim that a black object on your side will not show up against the black background. Once again, I'm pretty sure his info is now completely out of date. The TSA has been upgrading the scanners so they no longer show the "nude" picture. Just last month we showed an image of what the new machines show:
Now, it is true that Corbett was able to get through the machines with a metallic box in his side pocket, and that's his proof. He does this twice. While, again, I'm not impressed by the machines, I don't think this is "proof" in the sense that Corbett believes. First of all, official tests show that there's a ridiculously high error rate with these machines -- they let through "bad stuff" all the time. So, I agree with Corbett that the machines are a complete waste and should be done away with, but I don't think one guy going through the scanners twice without getting stopped for a little metallic box in his pocket... is absolute proof that anyone can get through without getting stopped.
Of course, it seems worth pointing out that a metal box is not a dangerous object, and the point of the machines (so we're told) is to stop threatening objects from getting through -- not just metallic objects. So it's possible that the TSA agents saw this thing in his pocket and immediately saw that it wasn't something dangerous. Corbett's test was whether or not the scanners detect metal. But they're not metal detectors, so the test itself is flawed.
So, while I don't agree with the TSA's response to this video in which "Blogger Bob" somewhat angrily snaps back about how important TSA scanning is, I don't think Corbett's claims are that convincing and I'm surprised at how much press it's been generating. Yes, the scanners are probably pointless, and it's all security theater, but that doesn't mean we should all stop thinking through the details on videos that potentially show some weaknesses in these machines.