Geez, just think of the harm those things could do.
There could be some real cloak-and-dagger applications.
Hadn't thought of that. Will be dangerous, and perhaps also very beneficial -- for the most advanced countries in the world. In the distant future they might engineer trillions of the things designed to look for one person (some future bin Laden), passing from person to person, checking genes, until they find him, and then . . . beddy-bye, binny!