OSS Death's Head Stamp
During WWII, the OSS produced this stamp in an effort undermine the morale on the German homefront. The problem was getting the mail infiltrated into the German postal system and an ingenious method was devised. Captured German military postal officers were interrogated and the US obtained the schedules of mail trains. German mail bags were counterfeited and filled with the phony mail. The trains were strafed and bombed, with some of the attacking planes dumping the bogus bags into the melee. When the mess was cleaned up, the OSS mail bags were picked up with the scattered German mail. Typically the letters were addressed to the spouses of senior military and party members, alleging adulterous affairs, reporting battlefield injuries, etc. in order to destroy the enemy morale.
