Once the govt. screws up and gives someone a visa who should be on a no-fly list, the ball shifts to the airlines, which are a business, who have to ensure the safety of passengers; if, as in Detroit, a terrorist manages to get on a plane, the ball shifts to the passengers, the pilot and the stewardess. As we see, the passengers, can overcome a terrorist. The pilots have guns, the stewardesses are trained to overcome a terrorist. As we see, if the final stage is reached, it depends on the passengers and crew to subdue the terrorist.
Second rocket fired from Gaza explodes inside Strip (Haaretz)
from the article: In Israel, racial profiling doesn't warrant debate, or apologies