“Loose tweets destroy fleets.” That’s the slogan of the United States Air Force’s latest operations security (OPSEC) campaign, and if the phrase sounds familiar, don’t be surprised. We collected 50 propaganda posters from World War II that show an age when keeping military secrets was a matter of life or death.

In the 1940s, operations security meant avoiding talking or writing openly about military actions, in order to keep critical information from reaching the ears of adversaries. In the social media age, things have become bit more complicated, as the USAF Central Command explains:

Keeping quiet about operational information is vital to ensure military members stay safe on a daily basis. Social media can be a useful tool to stay connected to friends, family, and quick entertainment. However, there is sometimes a fine line between letting your friends see what you’re up to and providing an adversary critical information about your connection to the military and its mission.

During World War II, the Office of War Information issued dozens of propaganda posters designed by well-known artists at the time, to persuade Americans–civilians and military personnel both– to support the war effort by keeping quiet about what they might know about.

The following 50 are our favorite posters:

Keep it to yourself buddy, 1943. Designed by Russell Kraus (St. Louis, Missouri).

Source: Library of Congress


Keep mum, Loose talk costs lives, 1943. Artist: William B. Finley.

Source: Library of Congress


Keep mum chum, 1943. Designed by William B. Finley.

Source: Library of Congress


Let me do the talking! Serve in silence. 1943. Designed by Homer Ansley.

Source: Library of Congress


Careless talk costs lives, 1943. Al Doria.

Source: Library of Congress


This happens when you talk to others about ship sailings, 1943. Artist: John McCrady.

Source: Library of Congress


Keep mum – the world has ears, c1941. Artist: Edward T. Grigware.

Source: Library of Congress


I pledge allegiance and silence about the war, 1943. Designer: Thomas A. Byrne.

Source: Library of Congress


“Censored” Let’s censor our conversation about the war, 1943.

Source: Library of Congress


Someone Talked, 1942. Designed by Frederick Siebel.

Source: Wikimedia Commons


Loose lips might sink ships, 1943.

Source: National Archives


Silence means security, 1941-1945.

Source: National Archives


Award for careless talk: don’t discuss troop movements, ship sailings, war equipment, 1944. Artist: Stevan Dohanos.

Source: Northwestern University


I’m counting on you! 1943. Artist: Leon Helguera.

Source: Northwestern University


Less dangerous than careless talk. 1944. Artist: Albert Dorne.

Source: Northwestern University


Don’t tell him what you know about .... troop concentrations, departures .... arrivals, 1941. Artist: Russell W. Kraus.

Source: Library of Congress


Who wants to know? Silence means security, 1943.

Source: Northwestern University


A careless word... a needless loss, 1943. Artist: Anton Otto Fischer.

Source: Northwestern University


A careless word... a needless sinking, 1942. Artist: Anton Otto Fischer.

Source: Northwestern University


A careless word ...another cross, 1943. Artist: John Atherton.

Source: Northwestern University


Because somebody talked! 1944. Artist: Wesley.

Source: Northwestern University


Wanted! For murder. Her careless talk costs lives, 1944. Creator: Victor Keppler.

Source: Northwestern University


Careless talk... got there first, 1944. Artist: Herbert Morton Stoops.

Source: Northwestern University


If you talk too much, this man may die, 1942. Artist: Valentino Sarra.

Source: Northwestern University


Bits of careless talk are pieced together by the enemy, 1943. Artist: Stevan Dohanos.

Source: Northwestern University


Somebody blabbed, button your lip! 1942. Artist: Albert Dorne.

Source: Northwestern University


If you tell where he’s going... He may never get there! 1943. Artist: John Philip Falter.

Source: Northwestern University


Somebody blabbed, button your lip! 1942. Artist: Albert Dorne.

Source: Northwestern University


He’s watching you, 1942. Artist: Glenn Ernest Grohe.

Source: Northwestern University


Careless talk got there first, 1944. Artist: Ray Prohaska.

Source: Northwestern University


Don’t be a sucker! Keep your mouth shut. 1943

Source: Library of Congress


Watch yourself pal! Be careful what you say or write! 1941

Source: Wikimedia Commons/National Archives


Some birds talk too much. 1942

Source: Wikimedia Commons/National Archives


Beware. 1942

Source: Wikimedia Commons/National Archives


Protect his future ...watch your tongue. 1942

Source: Wikimedia Commons/National Archives


Sh-h-h silence means security, 1942

Source: Wikimedia Commons/National Archives


Please don’t gamble with your life! 1942

Source: Wikimedia Commons/National Archives


Keep your [mouse] shut! 1941

Source: UNT


Quiet! Loose talk can cost lives, 1941

Source: Wikimedia Commons/National Archives


Someone talked! 1942

Source: Wikimedia Commons/National Archives


Silence means security, 1941

Source: Wikimedia Commons/National Archives


Allure or a lure? 1941

Source: Wikimedia Commons/National Archives


The M-1 does my talking! 1941

Source: Wikimedia Commons/National Archives


Loose talk can cost lives, 1942. Artist: Stevan Dohanos.

Source: X-Ray Delta One


Enemy ears are listening, 1942. Artist: Ralph Illigan.

Source: UNT


Loose talk costs lives. Back up our battleskies! 1942

Source: Wikimedia Commons/National Archives


Loose talk can cause this, 1941

Source: Wikimedia Commons/National Archives


Loose talk can cost lives, 1941

Source: Wikimedia Commons/National Archives


Loose talk can cost lives, 1941

Source: Wikimedia Commons/National Archives


Don’t kill her daddy with careless talk, 1941

Source: Wikimedia Commons/National Archives