HISTORY OF COVERT SAFES!
CAN SAFES
Can safes were used because they looked like everyday product that could be used to give instructions to someone, and to make cash payments. Products such as drink cans can be stuffed with instructions telling a spy what mission they needed to carry out, and other details. When the mission was accomplished then a spy could "send" a message back to his handler where they could find the stolen papers, products, or a micro film that was hidden by a spy. The spy would then locate another hidden can safe that provided cash for services rendered.
These techniques were used so that a spy would not be reveled. A spy may not know his handlers true name, or what they looked like, and a spy could watch his cache of hidden safes to see if others are watching the safes to see if there is a trap. A spy could send someone to fetch a can safe for them to see if they would get apprehended.
Things would get really crazy if there was a lot of information that had to be passed back in forth between a spy, and their handler. You are probably asking why someone would go through all of this trouble to communicate. One reason may be that it is not safe to use radios. There may be radio direction finding teams that can orient in on a transmission therefore giving away the position of the radio. Another reason is that someone with a scanner can listen on your converstaion, and they can find out the details of your plans, and catching you in the act of spying! If the coversation is recorded then perhaps the spy could be identified by their voice!
Hidden safes have been used for many, many years. They have been used by the wealthy to hide their assets from friends, relatives, enemies, business partners, and also marital partners!
The art of diversion can be studied with the Egyptian Pyramids where false chambers would be made to fool raiders where the gold would be located.
http://www.thesmokinggun.com/archive/years/2007/0118071mexico1.html
JANUARY 18--Miami police are investigating NFL star Michael Vick after airport screeners yesterday seized a water bottle from him at a security checkpoint and later discovered that the bottle included a "concealed compartment" that appeared to contain a small amount of marijuana!
