In 1968, with the US war against Vietnam raging, anti-war veterans and the anti-war movement as a whole in the US increasingly put the spotlight on the US use of napalm. Napalm is burning jellied gasoline dropped on humans engineered to stick to skin and cause horrible burns. According to the wikipedia page on napalm, http://en.wikipedia.org/wiki/Napalm "388,000 tons of U.S.
One interesting thing about this stunt is that there is no record of it other than the Yippies' wonderful testimony. We believe that it actually happened, but it shows that storytelling is the most important part of any action of this sort.