Espionage has been with us since early time. But the immigrant/melting pot based nature of the United States and our relatively late involvement in WWII made 1940s America a lucrative environment for spies and potential saboteurs.
Naturally, the dangers and concerns of national security intensified whtn the U.S.entered the war and America's overseas military and homeland patriots urgently needed additional protection. The U.S. Government had a great need to alert its' military and private citizens to the presence of enemy spies and saboteurs lurking in American Society.
A major advertising blitz involving all media eventually produced thousands of remarkable "careless talk" posters to warn people that small snippets of information regarding troop movement or other logistical details would be used by the enemy and could easily compromise national security and U.S. military personnel safety.
This striking and effective poster was designed in 1942 by famous artist/illustrator Stevan Dohanos. It's a realistic painting of half sunk cargo ship headed for the bottom of the ocean. The poster, which depicts an all too common news story of the time, involves a ship sunk by a German U-boat.