The foiled al Qaeda plot to put an underwear bomber on an airliner bound for the U.S. is raising the question of whether the sophisticated device would have slipped past airport screening.

Meanwhile, a new plot has been uncovered that reveals terrorists are planning to plant bombs in computers, cameras, and even pets that are then boarded onto aircraft.

An official working in U.S. counter-terrorism, who spoke anonymously, said "good intel, kill or capture are infinitely more desirable actions for stopping would-be attackers than relying on airport-screeners who hassle everybody, including people who hold classified clearances."

Earlier this week we learned the unexploded bomb was stopped at its source in Yemen, and would not have set off metal detectors because it was made of a non-metallic explosive.

Full body scanners do detect non-metallic explosives and they are currently in use at 170 domestic airports.

Of course, there are thousands of airports in the U.S.