Today, the inconveniences - and indignities - are familiar to every air passenger. And train depots like 30th Street Station are patrolled by armed guards and police dogs, while even subway stops are subject to random VIPR ("Visible Intermodal Prevention and Response") sweeps, with federal officers swabbing chemicals on bags to test for explosives, beneath posters that implore commuters, "If you see something, say something."
An army of 50,000 transportation security officers has been deployed around the country, and since 9/11, the Transportation Security Administration has spent $57 billion on aviation security.
So far, it's worked.
No plane or train in the United States has been successfully attacked since 9/11. Every day, federal screeners thwart attempts big and small to breach security at airports and other transportation hubs.
In the last four years, the TSA has seized 3,400 guns and more than 400,000 "incendiary items" from airline passengers.
Just last week, the TSA reported catching 18 guns, six "artfully concealed prohibited items," and seven passengers who were arrested after investigations of "suspicious behavior or fraudulent travel documents."
But at what cost?
Individual rights
Critics say the government's techniques invade privacy - sometimes in humiliating ways - erode individual rights, and threaten the health of travelers and screeners alike from scanning radiation.
And the trend, said Jay Stanley, a senior policy analyst at the American Civil Liberties Union, is toward more intrusions.
"When a frightening thing happens, like the Christmas bomber, the media and politicians jump all over it, clamoring for government to 'do something,' and the big security bureaucracies like TSA put their gears in motion," Stanley said. "It sort of develops a momentum of its own."
