They most certainly will know!! As a law-abiding citizen, I will blaa blaa, blaa! Bleh blaa...
Besides, since they've published the "smart dust", they have a way of incorporating a sensor, transmitter, signal processor and a powersource to a smaller space than 1 cubic mm...
Um, no? "Smart Dust" was published in March, and consists of a unit the size of 1 cub.mm, and contains the fore mentioned qualities. And a superpower such as the USA, wouldn't allow it to be published unless they already have a better thing to use in espionage and surveillance. It'd be idiotic thing to do.