Yesterday, I heard on TV news the audio tape of a conversation between the control tower at JFK and the pilot of the plane carrying the alleged Times Square attempted-bomber in which the controller tells the pilot to abort his taxiing and turn left at the next opportunity AND RETURN TO THE TERMINAL. The pilot acknowledged and affirmed that he would do so. Today, the news emphasized that the plane never left the gate. Hmmmm.
Today, also, Dept. of Homeland Security stated that the system worked.