Homefront Propaganda in Germany and the U.S.A.: Espionage
Being a good citizen meant keeping quiet about sensitive information -- troop movements, for example. Posters reminded people that spies could be lurking anywhere, monitoring conversations -- in public places, on telephone lines, or intercepting letters.
Pst! no date
The shadowy figure of a spy hovers over a couple dining in a restaurant.
Keep mum. The world has ears. 1941-1943
The Thirteenth Naval District of the U.S. Navy created this poster.