Originally Posted by
GUWonder
I doubt that it’s just for the latter, since just beyond it passengers can mingle with passengers for a variety of destinations that are not in the US.
Indeed, which is what makes this "random" aspect totally meaningless.
If, as you point out, there is a danger that even these randomly-checked passengers can again pick up something disallowed by "mingling" with the airside crowd, that means that they are not convinced that airside is actually "clean", and therefore rather than random checks, everyone should be checked.
I assume this is just another example of "security theatre", and that the facilities and personnel used up on this off-Broadway production (
) would be better employed filling out the chorus line on the main Broadway show, i.e. at the central security checkpoints where waiting times are often long enough as it is, due to lack of staff and closed security lanes.