It is very likely that a large (15-20 cm in diameter), irregularly-shaped, cm-thick pancake with beveled edges, taped to the abdomen, would be invisible to this technology, ironically, because of its large volume, since it is easily confused with normal anatomy. Thus, a third of a kilo of PETN, easily picked up in a competent pat down, would be missed by backscatter “high technology”. Forty grams of PETN, a purportedly dangerous amount, would fit in a 1.25 mm-thick pancake of the dimensions simulated here and be virtually invisible. Packed in a compact mode, say, a 1 cm×4 cm×5 cm brick, it would be detected.
Of course it’s no surprise that the TSA’s fancy new backscatter scanners could be so easily duped (apparently, they’re not very good at detecting strategically placed thin wires and razor blades either), but if you really want to get devious about it, the softest target in our air transportation system might just turn out to be TSA itself.
In fact, if I were a dedicated suicide bomber (and just to be clear to federal authorities, I’m not), I’d pack a rolling, carry-on suitcase with as much explosives as possible, pick the busiest time of the day, wheel it through the snaking security line until I was in the very middle of the crowd, and then… BOOM!
Depending on the sophistication of the device, such an attack would kill and injure dozens, possibly hundreds, and achieve the same catastrophic impact on the airline industry without having to devise a way to sneak a weapon through security. And since the target is created by the screening process itself, such attacks would be virtually unstoppable, as any attempt to expand the security perimeter would merely create more targets.
Meanwhile, the traveling public might be much less sanguine about waiting in line for TSA’s security theater if they feared the very act made them sitting ducks to the real terrorist threat.
Now I know some of you may find my public speculation on TSA security flaws to be irresponsible, perhaps even criminal, but I’m a big believer in the philosophy that drives the open source community on such matters: that publicizing security holes is the first step toward closing them. For example, had we imagined (as the Israelis did) that terrorists might commandeer airliners to be used as building-busting weapons, the 9/11 attack might have been entirely avoided.
For in the end, I don’t just oppose the TSA’s invasive new porno-scanners and “enhanced” pat-downs because I find them offensive, I oppose them because I feel they ultimately make us less safe by consuming resources on merely giving us a false sense of security.