The first layer of actual security that greets travellers at Tel Aviv's Ben Gurion International Airport is a roadside check. All drivers are stopped and asked two questions: How are you? Where are you coming from?
"Two benign questions. The questions aren't important. The way people act when they answer them is," Sela said.
Officers are looking for nervousness or other signs of "distress" — behavioural profiling. Sela rejects the argument that profiling is discriminatory.
"The word 'profiling' is a political invention by people who don't want to do security," he said. "To us, it doesn't matter if he's black, white, young or old. It's just his behaviour. So what kind of privacy am I really stepping on when I'm doing this?"
Once you've parked your car or gotten off your bus, you pass through the second and third security perimeters.
Armed guards outside the terminal are trained to observe passengers as they move toward the doors, again looking for odd behaviour. At Ben Gurion's half-dozen entrances, another layer of security are watching. At this point, some travellers will be randomly taken aside, and their person and their luggage run through a magnometer.
"This is to see that you don't have heavy metals on you or something that looks suspicious," said Sela.
You are now in the terminal. As you approach your airline check-in desk, a trained interviewer takes your passport and ticket. They ask a series of questions: Who packed your luggage? Has it left your side?
"The whole time, they are looking into your eyes — which is very embarrassing. But this is one of the ways they figure out if you are suspicious or not. It takes 20, 25 seconds," said Sela.