Warning: Careless Talk May Help the Enemy. Be on Your Guard

A text-only sheet in nested black and red frames lists seven subjects not to discuss: ship movements, defence plans, munitions factories, troop movements, harbour facilities, aircraft production and supply stores. The red warning that talk 'may help the enemy' sets an unseen threat against ordinary conversation (fear-appeal).

Propaganda techniques used in this poster

Fear appeal

Date

1941

Period

Second World War

Made by

Director of Public Information, Ottawa, under authority of the Minister of National War Services (J. T. Thorson)

Region

North America

Country

Canada

Medium

Poster

Issuer type

State

Regime

Mackenzie King Government

Leader

William Lyon Mackenzie King

Audience

Domestic public

Purpose

Warn or inform

Themes

Security and surveillance, Home front, War and the military

Event

World War II

Source

Identified Openly sourced: the speaker is who they say they are

Source

U.S. National Archives and Records Administration, Record Group 44, World War II Foreign Posters, retrieved October 3, 2026

Rights

Public domain (Canadian Crown copyright, 50 years from publication, expired; no URAA restoration)
Director of Public Information under the Minister of National War Services, Ottawa. U.S. National Archives (RG 44).

WARNING
CARELESS TALK
MAY HELP THE ENEMY

DO NOT DISCUSS
SHIP MOVEMENTS
DEFENCE PLANS
MUNITIONS FACTORIES
TROOP MOVEMENTS
HARBOUR FACILITIES
AIRCRAFT PRODUCTION
SUPPLY STORES

BE ON YOUR GUARD

Issued by the Director of Public Information, Ottawa
By authority of Hon. J. T. Thorson, Minister of National War Services