(Reuters) Jeffrey Heller - Pini Schiff, former head of security at Tel Aviv's Ben-Gurion Airport, questioned new rules banning carry-on electronics on flights to the U.S. and Britain from parts of the Middle East and North Africa. "What can explode in the plane while it's in a passenger's hands can also explode in a cargo hold, because if you put a timer or a barometric pressure switch on it, you endanger the flight to the same degree," he said, recalling the destruction of Pan Am 103 over Lockerbie, Scotland, in 1988 by a bomb that Libyan agents hid in a radio-cassette recorder in the jumbo jet's hold. At Ben-Gurion Airport, security screening is a combination of high-tech and thinly disguised profiling. Before reaching the main terminal, vehicles stop briefly at a security checkpoint where guards speak with the car's occupants. Small cameras point at license plates, apparently checking numbers against a data base. Other plainclothes guards are stationed at the doors to the terminal. Once inside, foreigners are asked who packed their bags and about their broad background by screeners who attend a course lasting several months. Bags and laptops are placed on trays for electronic screening, while shoes, belts and watches usually stay on. All luggage of departing passengers headed to the hold is screened by a system that "works on the same principle as medical CT scans," Schiff said.