Recent incidents in which airports had to be emptied and the passengers rescreened (delaying dozens of flights) may be the result of disgruntled employees of the current airline security companies who fear they will not have jobs with the new uniformed federal security service. In one case, a metal detector was unplugged, possibly by such an employee. The FAA is looking into ways to minimize the problem by compartmentalizing airports (so that only part of it would have to be emptied) and by using equipment that is harder for employees or pranksters to disable.--Stephen V Cole