According to The Canadian Press, a recent report by the U.S. Defense Security Service (a branch of the DoD) revealed that at least three American contractors who visited Canada returned home with more than a souvenir toque and supply of Tim Horton's coffee, finding Canadian coins bugged with miniature transmitters when they unloaded their pockets. Apparently, the bugs were planted by international spies hoping to pick up information about military technology from the contractors at conventions, seminars, or exhibits in the country. While the exact type of transmitter hasn't been revealed, speculation seems to suggest an RFID chip, although as former RCMP officer and current security consultant told the CP, the whole scheme isn't exactly the most foolproof one. Not only would a reader of some sort have to be nearby to pick up the signals from the coins, there's also of course no guaranteeing how long the individual will actually hold onto the coin before that poutine craving forces them to spend it.
[Thanks, Dave W]
Update: Alas, it appears that this bit of cross-border intrigue may have been too good to be true, with The Globe & Mail now reporting that the case of the bugged pocket change has been overblown, according to a US official familiar with the case. The official added that some "odd-looking" coins did trigger some suspicions when they were found, but ultimately posed no risk or danger.