As a matter of fact, I do have that... in a box someplace...
What made me connect the two ideas was a concept they tried during the Cold War. Two targets always sat in a fenced courtyard on the same bench talking business, so there was no chance of being overheard with a bug. The Agency developed a round that could be fired into a tree right about the two. The slug had a tiny transmitter and hair sized antenna. They made the shot but the bark was too rough and wouldn’t serve as a flat plane well enough to pickup the conversation. Some operations were successful and some not. This one was not. It is worth noting a number of Russian citizens who gave there lives in support of our goals against the Soviet Union.