'On at least three separate occasions between October 2005 and January 2006, cleared defense contractors’ employees traveling through Canada have discovered radio frequency transmitters embedded in Canadian coins placed on their persons.' (p. 32)
See, that's what technological progress is good for.
- Washington Times:
Foreign spy activity surges to fill technology gap
- Globe and Mail:
If you're a spy, Canadian money talks
Spies embedding tiny transmitters in Canadian coins, U.S. report says
Thanks to Kerstin for the interesting info.