Q
The machines have shown up in the wake of the so-called underwear bomber, who tried to blow up a plane with chemicals stored in his briefs. Would this technology have stopped him?
A
The guys who make the machines have said, “We wouldn’t have caught that.”

Q
So what kind of attack will this prevent, that otherwise might be successful?
A
There are two kinds of hijackers. There’s the lone nutcase, like someone who will bring a gun onto a plane because, dammit, they’re going to take the whole plane down with them. Any pre-9-11 airport security would catch a person like that.

The second kind is the well-planned, well-financed Al Qaeda-like plot. And nothing can be done to stop someone like that.