http://denver.cbslocal.com/2011/05/08/4-arrested-after-suspicious-incident-at-dia/
DENVER (CBS4) – Four people were arrested after a suspicious incident at Denver International Airport.
The incident happened Saturday morning at the south end security checkpoint. Airport personnel noticed someone videotaping the security lines. Police then confronted the person with the camera and the three people in line who were being taped. Two of those people did not have IDs or boarding passes.
Police arrested the man with the camera and the three people in line. Police say they don't know what the group was doing. They were arrested on suspicion of interfering with a transportation facility.
Security was stopped for a few minutes and police conducted a security sweep but didn't find any problems.
http://newyork.cbslocal.com/2011/05/08/schumer-calls-for-do-not-ride-list-for-amtrak/
Schumer Calls For 'Do Not Ride' List For Amtrak
Too Much Fear? Package Threat Forces Evacuation Of Dallas DART Station
http://dfw.cbslocal.com/2011/05/07/bomb-threat-forces-evacuation-of-mockingbird-dart-station/
It's called security creep.