W. David Stephenson has been thinking quite a bit about the right way to counter the threat of terrorism. He argues (correctly, in my view) that the traditional military response is counter-productive at best, and that the only effective way to handle a distributed network of opponents is with a distributed network of protectors. He's talked about some of these ideas before, but in light of the London attacks, he has brought them together into a single post, "Smart Mobs for Homeland Security."
Who would it comprise? All of us: My concept... was to harness all of these wireless devices in the public's control into an ad hoc, self-organizing system to both inform and empower the general public to play a significant partnership role in homeland security. A number of David's proposals will sound familiar to WorldChanging readers, in part because we've pointed to some of them before, and in part because he's definitely thinking along the same lines as we have been with the use of open, collaborative efforts to ensure our own safety.
Wouldn't it be better to think about how to prevent terrorism instead of efficiently responding to it after the fact?
If you think about a transportation system which uses smaller units of conveyance, which can be linked together on the fly, and also has both low-speed, local capabilities as well as high-speed, long-distance capabilities (like maglev PRT in an evacuated tube system), then it gets around the entire vulnerability of putting a ton of people together in one confined space. Also, since the vehicles themselves are smaller, they wouldn't need to be put nearly as far into the ground as a subway.
The vehicles themselves would essentially be a smart mob, interacting with the other vehicles around them (their position, speed, looking for signs of rapid deceleration, etc). Plus, it would be much easier to develop a security system for such a thing, since user authentication would be necessary to use the vehicles and the system. It would also be far more tolerant to any breakdowns (just like the Internet), since there would be multiple rerouting opportunities in case a certain segment of the system became disabled.
About the only limitation of the system would be traveling across long distances of water, or traveling long distances to get around water (eg, building a line up to Alaksa to get to Asia) - so it could be supplemented by transoceanic air travel where necessary. Otherwise, one could foresee it replacing most autos, trucks, trains, buses, and airplanes, both for passenger and freight.