"This shocking breach undercuts the public's confidence in the security procedures at our airports," said Senator Susan Collins, R-Me., ranking Republican member of the Senate Homeland Security and Governmental Affairs Committee. "On the day before the Senate Homeland Security Committee's hearing on terrorist travel, it is alarming to learn that the Transportation Security Administration (TSA) inadvertently posted its own security manual on the Internet." 

It's worth noting that if the program effectively precluded the possibility of getting on a plane with the means to interfere with the flight, there wouldn't be any reason to keep it a secret. Beyond that, Sonny Barger pointed out years ago that three people can keep a secret as long as two of them are dead ...