Within the next year or two, the U.S. Department of Homeland Security will instantly know everything about your body, clothes, and luggage with a new laser-based molecular scanner fired from 164 feet (50 meters) away. From traces of drugs or gun powder on your clothes to what you had for breakfast to the adrenaline level in your body—agents will be able to get any information they want without even touching you.
http://gizmodo.com/5923980/There has so far been no discussion about the personal rights and privacy issues involved. Which "molecular tags" will they be scanning for? Who determines them? What are the threshold levels of this scanning? If you unknowingly stepped on the butt of someone's joint and are carrying a sugar-sized grain of cannabis like that unfortunate traveler currently in jail in Dubai, will you be arrested?