Did you know that there was a 17th century plot to use hats as bioweapons in Heraklion against the Ottoman troops that besieged the city! Michiel Angelo Salamon, a 17th century scientist planned to weoponise the bubonic plague by painting it onto hats. He managed to harness the plague by distilling it from the spleen. The plan was to paint it onto goods that besieging Turks were likely to buy such as hats known as Albanian fezzes. Proof of this plot was found in historical letters, but it is unclear if it ever was executed.
Source: Eleni Thalassinou, 2015, NewScientist, 28 Nov 2015, p. 15