Check the Sofa for Loose Change

Time to gather up all that loose change. According to this CNN story:

"In a U.S. government warning high on the creepiness scale, the Defense
Department cautioned its American contractors over what it described as a new
espionage threat: Canadian coins with tiny radio frequency transmitters hidden
inside.
The government said the mysterious coins were found planted on U.S.
contractors with classified security clearances on at least three separate
occasions between October 2005 and January 2006 as the contractors traveled
through Canada.
The U.S. report doesn't suggest who might be tracking American defense
contractors or why. It also doesn't describe how the Pentagon discovered the
ruse, how the transmitters might function or even which Canadian currency
contained them.
Further details were secret, according to the U.S. Defense
Security Service, which issued the warning to the Pentagon's classified
contractors. The government insists the incidents happened, and the risk was
genuine."

The story goes on to name China, Russia and France as the chief suspects. All three countries apparently run spy rings in Canada virtually unnoticed.
The Canadian spy agency, CSIS, says it has no knowledge of the coins.
So I guess all those crazy paranoids who've been telling us for years that the government keeps track of us with transmitters in our money weren't so - ahem - looney after all.