Image Sources:
Title Image: A group of Polish Jews converses in a reading room in front of a large map of Poland, before 1939, United States Holocaust Memorial Museum, courtesy of Dr. Anna Wieteska, Photograph Number 25452 (cutting).
Image 1: British poster “Careless talk costs lives. Mr Hitler wants to know!”, 1939 – 1945, Collections of The National Archives (United Kingdom), catalogued under document record INF3/238 [Public domain], commons.wikimedia.org/wiki/File:INF3-238_Anti-rumour_and_careless_talk_Mr._Hitler_wants_to_know.jpg
Image 2: Jews converse outside in the "Sammelstelle" [gathering place] in the Kovno ghetto, 1941 – 1944, United States Holocaust Memorial Museum, courtesy of George Kadish/Zvi Kadushin, Photograph Number 81110 (cutting).