I've been discussing this on Hacker News (https://news.ycombinator.com/item?id=5579369) and probably deserve my downvotes. I guess it's still too soon. But I have an argument that I've felt since earlier today, and which I've been discovering its articulation slowly as I argue for it, that goes like this:

It shouldn't be possible for two guys, 26 and 19 years old, to freeze a major city with a few hundred dollars worth of pressure cookers and gunpowder. If it was possible to knock-out all of Boston from the Internet with a cheap rig, we'd be putting all our resources into fixing security and protocols to make it so that such an inexpensive attack could never have such an enormous economic cost.

I have a friend who was traveling from Virginia to Connecticut on Amtrak only to be halted at Penn Station in New York City. They'd boarded their train just after 12pm today, but at 12:30pm service was cancelled north of New York City at the request of authorities due to the manhunt in Boston. She had to take a subway up to Grand Central Station to board a commuter train to complete her trip.

Schools were closed. University campuses shut down. According to a sparring partner, a possible 600,000 people within the Boston area were affected: the public Metro system was shut down until 6pm, private taxi service suspended until 11am. Whole communities--Watertown and possibly neighboring towns--ordered to remain indoors. An entire city was anesthetized.

On Twitter, I started calling it the "Boston Anaphylaxis".

This shouldn't be possible. The security guru Bruce Schneier once remarked on airport security as "brittle", meaning that it takes very little to break so much. If someone passes a bag over a security barrier they can't just shut down a single gate, they must shut down the entire Terminal and--as in the LAX evacuations after 9/11--the whole airport.

I think we can reduce terrorism by reducing the consequential price of dealing with the aftermath of terrorism. If every threat, shooting, bombing and hijacking yields ever decreasing returns, then the tactic will fall out of favor among the radicalized.