[EGPWS]

The point is that there are warnings at airports, TELLING people to look around them and REPORT suspicious behavior.

And TSA testing people employed at airports to verify their vigilance in reporting and stiff fines if one does not pass the test! ; )

[FairOpinion]

TSA probably just doesn't want people to fall asleep at the airport and miss their flights, so they try to keep them alert and doing something -- that's the only reason for the warning, I am sure. (/sarcasm)