Nothing, except that bags where scanned prior to 9/11.
What was essentially added was prohibitions to take a nail clipper onto a plane (which, of course is utterly ludicrous), the rules regarding liquids and the whole cowboy attitude (apparently mostly in the US).
Reinforcing the cockpit doors was actually one of the better ideas. Unless, that is, you have a psychotic, suicidal first officer. But that's a whole different story and anyway couldn't have been caught by airport security.
What was essentially added was prohibitions to take a nail clipper onto a plane (which, of course is utterly ludicrous), the rules regarding liquids and the whole cowboy attitude (apparently mostly in the US).
Reinforcing the cockpit doors was actually one of the better ideas. Unless, that is, you have a psychotic, suicidal first officer. But that's a whole different story and anyway couldn't have been caught by airport security.