"Crazy" and "military" would make an interesting set of Venn diagrams.
https://www.wired.com/dangerroom/2011/05/crazy-military-tracking-tech/
(...)
"Radar-Responsive Tag
"Sandia National Laboratories has carried out development on these radar-responsive tags, which are like a long-range version of the ubiquitous stick-on RFID tags used to mark items in shops. The radar-responsive tag stays asleep until it is awakened by a radar pulse. The tags in Walmart have a range of a couple of meters, Sandia’s tags can light up and locate themselves from 12 miles away.
"Image: Sandia National Laboratories..."
