Originally Posted by daw617

I don't know enough about the risks to know how significant this threat is, but the concern doesn't seem totally unreasonable.

Haven't you heard the stories about laptops being stolen at airport checkpoints by a pair of crooks working together? Crook #1 would be positioned just before you in line. When you put your laptop on the conveyor belt, Crook #1 would suddenly stop just short of the X-ray machine, preventing you from going through (e.g., he suddenly stoops down to tie his shoelaces and fumbles and stalls). While you are fuming at the delay, your laptop goes through the X-ray machine and pops out the other side. Meanwhile, Crook #2 -- who has been waiting patiently on the other side of the X-ray machine -- waits for your laptop to appear on the other side, snatches it, and melts into the crowd. Once Crook #2 has taken your laptop, Crook #1 walks through the X-ray machine as if nothing had happened. This isn't fiction we're talking about; this is real life. Are you certain this couldn't happen to your TOP SECRET material?

Or, there is a possibility for you to get separated from your bag if you are pulled aside for "continuous screening" immediately after going through the X-ray machine.

It may well be over cautious, for all I know, but it doesn't seem completely without foundation. If we're talking about material whose disclosure could cause "exceptionally grave damage" to national security, this kind of caution may well be appropriate. Perhaps some security officer has decided that it is safer to prevent putting couriers in a position where this could happen to them rather than teaching couriers about these risks and how to respond.