There was an interesting incident last week, where a TSA behavioral detection officer detected someone who turned out to have bomb-making equipment with which he was planning to fly.
Although there has been some media coverage, it was probably news to most people that TSA used behavioral detection. There are staff at a few US airports, with plans to roll out the program in more airports quite rapidly. As a program, it has been successful — about 1% of stops seem to produce arrests, which is actually a pretty good rate. Of course, almost all of these arrests are for crimes unrelated to air travel, which raises some difficult issues that will exercise the minds of those who are extremely keen on privacy (but note the existence of a Terry stop in the US which seems to me to more-or-less cover this case).
I’ve decided that when people use the word ‘profiling’ what they mean is predictive modelling based on arbitrary or intuitively derived attributes and models.
It isn’t appropriate to call this “behavioral profiling”. Its technical roots seem to come from two places. The first is Ekman’s work on microexpressions, which some people may be familiar with from Gladwell’s book, Blink. The idea is that all of us exhibit fleeting patterns of muscular use, primarily facial, that reveal parts of our underlying internal state. Some practice is evidently needed to learn to notice these in real time, but it can be done.
The second part is less public but seems to have been developed by the Israelis as a way to defend against suicide bombers. I’ve heard one talk by an Israeli about this (light on technical details), but they claim to have high success rates across a wide spectrum, for example including schoolboys.
In the conversation about the recent incident, many connections were drawn with air security at Ben-Gurion, the main airport in Israel. It’s not entirely fair to draw such comparisons. Ben-Gurion uses a defence in depth where, as I understand it, data analysis begins when you order your taxi to go to the airport (as well as the obvious analysis of flight manifests).