Leaflet bombs

The Explainer explains:

Capt. James Monroe invented the American propaganda bomb during World War II. Thousands of pieces of paper were stuffed into a laminated paper cylinder with a detonator and a delay, and then loaded into a B-17. The "Monroe bomb" exploded on the way down, sprinkling leaflets over enemy territory from a low altitude. The Air Force quickly developed more advanced versions of the same idea. For many years, their standard leaflet bomb was the M129, a fiberglass case that holds up to 80,000 flyers. . . .

. . . . According to the PsyWar Society—which publishes a quarterly magazine called The Falling Leaf—aerial leaflet propaganda goes back at least as far as 1806, when a British admiral used kites to drop messages on the French. The French used balloons to drop leaflets on the Prussians in 1870, and the practice continued at least until the Second World War. Twentieth-century armies also fired leaflets at each other in howitzer shells, grenades, and rockets.