Combine Dog Nose on my wrist & ET Call Home and what do you get?

Smart phones that "smell" and gps map trace explosive fumes - could help resolve terrorism attacks (and Cleveland shootings, and carbon monoxide poisoning, and pollution alerts) before they happen.

Here are links to this technology:

http://defense-update.com/20130820_sin-vapor_explosive_detectors.html [1]

http://www.gizmag.com/saper-explosives-detector-app/22614/

http://fortune.com/2014/11/04/a-better-bomb-detector-researchers-develops-device-that-can-sniff-explosives/ [2]

http://www.cbsnews.com/news/device-to-detect-tatp-explosive-used-by-brussels-terrorists-could-save-lives/

Combine these "sniffing" technologies with Distributed Sensor Networks [3] - similar to the existing wifi/mobile telephone networds that map seismic events in real time -

and we would be able to know when and where an exposive package passed a sensor -

Then what? How is the package isolated?

I certainly don't want to be the person who goes up the the package-person and says "Hi, my name is Joe, and my smart phone just told me you may be carrying a bomb?"

The point is that with sniffing tech in fixed locations and on people combined with widely distributed data collection and automated gps locating of specific chemical smells we could have a very useful communications system.

Would every smart phone have the system or would smart phone owners have to opt in? - A constitutional question here in the USA.

Would the sniffing application be able to be "programmed" to smell certain chemicals (say carbon monoxide at home or in your car) and while allowing de-selection of other chemical fumes like gun powder - so you wouldn't inadvertently out the guy on the bar stool next to you at the JACK in Cleveland (where concealed carry is not allowed)? Oh, so complicated.....