[1] Examples in espionage include dead drop spikes for transferring items to other people, and hollowed-out coins or hollowed out teeth for concealing something - such as microfilm or a suicide pill.
Starting in the First World War and still continuing today, military personnel use ammunition casings to hide small amounts of critical information[citation needed] e.g. encryption/recognition codes or navigational grid references etc.
Given that ammunition can be found everywhere in a combat zone, it is very easy to hide or discard such items because they blend in easily.
Some of the most clever of these contraptions looked like large, ordinary black candles with a felt base concealing the opening.
[citation needed] In the early 1980s, the first magnetically or hydraulically actuated secret compartments, dubbed "urban traps" by the Drug Enforcement Administration, started to appear – often in door panels, dashboards, seats and roofs.
[3] In 2012, Alfred Anaya, famous among rich clients in California for his skill in installing sophisticated traps, was sentenced to more than 24 years in prison under U.S. federal law as a co-conspirator in a drug-trafficking operation.
A wide variety of commonly used personal care, household products and food containers with removable tops and bottoms are available.
Each of these diversion safes are indistinguishable from the genuine product, and can thus avoid detection, and they may even be weighted to feel full.
[4] A hollow container, fashioned to look like an Eisenhower dollar, is still used today to hide and send messages or film without being detected.
The half coin with intact edges would also have a pin-prick size hole drilled through its face, so the device could be opened by inserting a pin.
U-2 pilot Francis Gary Powers was issued with a hollow silver dollar containing a tiny, saxitoxin-impregnated needle,[5] to be used to commit suicide in case of capture by enemy forces.
Usually the only tool required is a screwdriver, the device can be opened up, have the majority of the electronic and mechanical components removed and replaced with the goods to be concealed.