Sensor networks to deter terrorism

My friend Sri has authored a very interesting paper on the use of sensor networks to deter terrorism. He notes that security checks at airports, in spite of being less than 100% reliable, have resulted in a dramatic decrease in aviation-related terrorist incidents in recent years. He goes on to argue that deploying sensor networks to detect nuclear, biological and chemical threats is now both technologically feasible and economical and that deploying such networks could dramatically reduce terrorist threats using WMD. The arguments he presents are rendered particularly potent in light of the recent Madrid bombings. Here's the abstract:

Abstract: Analysis of the RAND-MIPT terrorism incident database (1968-2003) reveals (1) government authorities have been unable to contain the accelerated rise in fatalities caused by terrorist use of conventional explosives, and (2) even imperfect sensor-based screening (passengers, luggage) instituted by civil aviation authorities has virtually eliminated bombings aboard commercial aircraft over the past decade. Sensors developed by R&D labs enabling remote (non-intrusive) detection of conventional, nuclear, biological, chemical bombs, have not seen widespread deployment outside of airports and some transportation hubs. Delaying the wide deployment and improvement of sensing capability, however imperfect initially, could prove to be a big mistake.

The paper is worth a full read - see here.