Smart Dust is RFID transmitters the size of a human hair with unique number strings for tracking purposes which are deployed in varying amounts for discrete or mass surveillance. It is a wireless/IoT enhancement of the classic Soviet use of spy dust to track foreign spies.
Discrete: Used in small quantities (hundreds of thousands individual RFIDs) to "paint" a specific target, be it a person or vehicle, and be able to track / mark that target remotely via wireless networks.
Mass - Used as a barrier or early warning surveillance tool. Deployed in large quantities (tens of millions of RFIDs) across multiple road networks in an enemy's rear area, or along a border. As people or vehicles track through the Smart Dust their movements are revealed, showing where an enemy convoy is headed, or what hidden paths smugglers are using to cross a border.
Takes proven techniques such as spy dust, chemical marking, or ground sensors, and automates it and makes it mobile, allowing for remote surveillance in real time. Multiple applications for intelligence / counterintelligence agencies, special forces, regular army, and missions like border protection. Signals piggyback on any available, open network allowing transmission, As IoT comes on-line, there will be tens of millions of devices they could piggy back off on for transmitting.
Has serious implications, both positive and negative for intelligence and counterintelligence agencies. Positive impacts for military's looking to move beyond static sensors like ground sensors used as far back as Vietnam to monitor the HCM Trail. Smart dust moves with the target, allowing not only for discovery, but observation of movement. Has probable non-military uses as well.