I'll have more on this later, but I had a very interesting conversation yesterday with John Pistole, the administrator of the Transportation Security Administration, and I wanted to bring you some of it, via my Bloomberg View column. Bruce Schneier, Goldblog's security guru (and the guy I used to break into airports with), has argued that the recently discovered underwear bomb 2.0, a more sophisticated device than the Christmas 2009 device that failed to ignite, doesn't mean that we should necessarily increase airport security, in part because if the bomb plot matures to the point where it's two hours away from completion, and the TSA is the last line of defense, then it is probably too late. I'm sympathetic to the Schneier argument. Pistole, not really sympathetic at all. Anyway, here's some of what Pistole had to say about the scanners and their ability to detect complicated, well-disguised bombs:

...Would the TSA have been able to identify this most dangerous anomaly in the crotch area, had al-Qaeda managed to build one in the U.S.?

(Pistole) mentioned the TSA's new scanning devices, now in use at about 180 airports.

"The advanced imaging technology gives us the best chance to detect the underwear-type device," he said.

The best chance? "This is not 100 percent guaranteed," he said. "If it comes down to a terrorist who has a well- concealed device, and we have no intelligence about him, and he comes to an advanced-imaging technology machine, it is still our best technology. But it's really an open question about whether the machine, or the AIT operator, would detect the device."

You can read more here.