One of the reactions to World War I breakout by artists was Dada. Essentially, it was a meaningless word to symbolize using any found object as art. One of the most outrageous use was a urinal put into an art competition by Marcel Duchamp as R. Mutt. It was artists reaction to the pointlessness of war overall. As we now know, the end of World War I led to an unsettled political environment in Europe leading to World War II repeating the same pointlessness of war. Many artists continue to use recycled materials. In my own art, I use a bit of this in my Political Pop art with reused symbols of the past to add mystery to the artwork.