TSA & Shoes – Blind, incompetent, and stupid

Just flew up to Anchorage and back on Alaska Airlines. It’s pretty much a monthly exercise in what Bruce Schneier refers to as “security theater”. [Note: Schneier’s blog, Schneier on Security, is a must read antidote to TSA.] It boggles the mind how some incompetent decided that using an uncalibrated x-ray scanner was an effective way to detect explosives. Without a densitometer or an IQI run at the same time as the scanned article, all the x-ray scanner does is provide a rough differentiation based upon density. So any material of approximately the same density as an explosive material, say C-4, shows up on the scanner looking like C-4, leading to either a unacceptably high level of false positives or a significant possibility of failure to detect. If it’s not shaped like a weapon, it will probably pass unnoticed.

And of course, you have to take your shoes off. After x-raying millions of shoes, TSA declared that they had a winner! Some unfortunate bloke in Anchorage won the “special treatment” after TSA found a toggle switch in his/her shoe.

TSA_Shoe1 Here’s the winning pair, courtesy of TSA…

TSA_Shoe2 Here’s the scary bomb parts…

OK, so found the proverbial needle in a haystack. Listen carefully… by itself, it doesn’t mean shit. The inference that TSA would like to impart is that the switch and wire is part of a nefarious terrorist plot. That is an unfounded inference, without merit. Without corroborating information, a toggle switch is just a toggle switch.

Why would someone have a toggle switch on a length of wire in their shoe? Ah, let me count the ways:

  • This was in Anchorage, Alaska. What happens when you’re out in the bush and your snowmobile has a frozen ignition because it’s -40? You carry a toggle switch and wire with you to bypass the ignition so you can get home before you freeze to death.
  • You’re a forgetful car thief, and forgot that you had that wire and switch to bypass car alarms in your shoe.
  • You shoplifted Radio Shack on the way to the airport.
  • You work in an electronics supply store and pilfered some parts for your home computer.
  • You’re a really stupid terrorist wannabe trying to see what you can get away with.
  • You’re a really stupid terrorist.

Notice that there is only one possible line of reasoning that is a terrorist, but several that don’t. So the probability is quite high (83% or higher) that the shoes do not belong to a terrorist.

[Update – 23 March 2008] – I posted basically the same information on the TSA blog a few days before this post. As of today, my blog comments to their shoe security is still unposted. Maybe TSA doesn’t like being told that their basic premises are flawed?

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2 Responses to TSA & Shoes – Blind, incompetent, and stupid

  1. Mike says:

    OK Here you go. Please look up a guy called Richard Reed. A toggle switch and wires inside a shoe. So do you know what explosives look like on their xray machines. You can find examples on google images. they look like green or orange blobs so if I saw that with your wire and toggle switch then yes I am stopping you if I am a TSA guy. Think about it a little bit before educate yourself a little you just pop off on a blog on the internet.

    • wilco278 says:

      Richard Reed – a couple ounces of explosive, det cord, and a match. Not a toggle switch and wires. Also notice that the wires and toggle switch are not connected. And no explosive. The point that I was trying to make is that TSA is assuming that everything that could be a weapon is assumed to be a weapon, whether it is a bottle of water, a screwdriver, or a toggle switch. There is no risk analysis being done, they’re merely applying paranoid movie plots to reality.
      As far as educating myself, I used to be certified to do non-destructive examinations of piping, using x-rays, among other methods. The work included x-ray machine calibration. That’s why I know a little about densitometers and IQIs for calibrating scanners. Yes, I have seen explosives on x-rays. They’re roughly the same shade of density as dense hardwood. The colors are artificial, based upon density readings.

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