The world's subway systems are so vulnerable when it comes to a terrorist attack that a headline in the satirical paper The Onion that read, "Unreleased Harry Potter book more secure than U.S. trains" is not entirely off the mark.
"The same characteristics that make them useful -- they bring a lot of people together and stop at several points in a city -- are the very thing that makes them a vulnerable target," said terrorism analyst Brian Jackson, referring to the nation's bridges and tunnels.
The official line of many politicians and experts is that it's only a matter of time until terrorists attack an American target again.
Officials Admit Mass Transit Security Is Daunting
The attacks on London's public transportation system have many U.S. commuters jittery in cities with subways and mass public transportation. In New York, Chicago, Philadelphia, Los Angeles, Washington, D.C., and San Francisco, vulnerable underground and aboveground lines are sitting ducks, say experts.
And the millions of people who ride the country's trains and buses were not reassured by Homeland Security Chief Michael Chertoff's recent admission that the nation's transportation systems take a back seat to airports when it comes to security.
"The truth of the matter is, a fully loaded airplane with jet fuel, a commercial airliner, has the capacity to kill 3,000 people," Chertoff told The Associated Press. "A bomb in a subway car may kill 30 people. When you start to think about your priorities, you're going to think about making sure you don't have a catastrophic thing first."
New York's Metropolitan Transportation Authority chief Peter S. Kalikow recently acknowledged that two-thirds of $600 million in security funding allocated to the state more than two years ago has not been used. Kalikow said he is waiting for the right technology to come to improve safety.
"They want to spend the money wisely, so I cannot blame the MTA in that respect," said terrorism analyst Mathieu Deflem, an assistant professor of sociology at University of South Carolina. "They also want to invest in 'proven' technology, and are keen on not spending money on fancy technology stuff of which we do not quite know how useful it is. I can agree with that."
And focusing exclusively on new technology would not be wise, he said. "Putting cameras everywhere is one thing. But equipment has to be maintained and people are needed to review the monitors and recorded activities."
MTA spokesman Tom Kelly said the MTA would spend half of the $600 million by the end of this year, to "harden the infrastructure on our bridges and tunnels.''
Convenient, Efficient … and Vulnerable
But ultimately, the very nature of a public transportation system limits how much can be done to protect them. Experts point to the fact that while people are willing to put up with the long lines and delays that go with tightened security at the airport, the same is not true for public transportation. Few commuters would be willing to wait at each station while their bags are inspected. So, figuring out how to secure these very open systems is nearly impossible. And, yet, the systems are very enticing to terrorists, experts say.
"There is a move away from very symbolically meaningful targets (WTC, Pentagon, White House) to people, ordinary folks, as many as possible, shock effect, hence the shift to mass transit (Madrid, London)," said Deflem.
So how could New York best spend the remainder of that $600 million to protect itself against a mass subway attack?
In Chicago, surveillance cameras on 700 new cars of the El trains are being put in place. It is now well-known that London's surveillance cameras have proven effective in pointing out the alleged suicide bombers. But cameras may do little to prevent an attack without security personnel monitoring the footage and adequate personnel standing by to react to any potential problem.
In Washington, D.C., buses are tracked with a satellite-based system. In San Francisco, every garbage can in the underground stations has been removed. The Houston transit authority is testing on-board cameras that can wirelessly transmit live color images.
For Now, Commuters Simply Live With Terror Risk
In New York City, there are more than 468 subway stations, which are used by 4.5 million riders daily, according to the city's transit officials. It's the busiest mass transit system in the country and experts say it is nearly impossible to secure the millions of passengers entering during rush hour carrying backpacks, shopping bags and gym bags -- or those wearing a vest bomb concealed under a baggy jacket. The MTA has had recent cutbacks in personnel. But the city's police department has added transit cops to the underground rails.
U.S. counterterrorism officials raised the terror threat level to "orange" for rail and subways following the July 7 attacks in London. Bomb-sniffing dogs and officers patrolling stations with machine guns could be seen in New York's subway system a few hours after the attacks.
New York City police said they would begin conducting random searches of packages and backpacks on Thursday -- the day of the second attack on London's subway system.
"We just live in a world where, sadly, these kinds of security measures are necessary," Mayor Mike Bloomberg told the AP. "Are they intrusive? Yes, a little bit. But we are trying to find that right balance."
Authorities said there is also a possibility that checks will be conducted on some bus and train passengers as well.
Jim Berard, Democratic spokesman for the House Transportation Committee, said the logistical difficulty in protecting subways and train stations is a top reason for congressional inaction.
"Can you imagine having to have a magnetometer at every bus stop?" he told the AP. "To that extent, it's one reason why we haven't tackled it. It's just so daunting."