In the midst of World War I, and in reaction against it, avant garde artists organized in beehives of audacious creativity, first in Europe and then the United States.
Marcel Duchamp's version of Mona Lisa is a prime example of the Dada spirit. Beloved as a beautiful painting that is mysterious, intriguing and compelling, Leonardo da Vinci's classic Mona Lisa was hated by some Dadaists because it had become a sacred cow -- no longer appreciated as a painting, but instead, commodified on postcards, posters and coffee mugs. Marcel Duchamp took a reproduction of da Vinci's painting, and drew a moustache and goatee on her face. Duchamp's audacity became a Dada statement. Ironically, Duchamp's daring deviltry itself became a classic -- widely replicated on postcards, posters and mugs.