The French blamed the Germans and the Germans counter blamed the French. After two years of being lost, people thought perhaps the Louvre had accidentally destroyed the painting. For two years it remained stolen until the thief answered an ad of an innocent art buyer in Italy in Fall 1913. A Letter from “Leonardo” arrived saying he had the stolen Mona Lisa. The art buyer working with police staged a sting. I won’t say who did it, but it was an Italian.
Italy went crazy that the Mona Lisa was found and it was exhibited throughout Italy before the Italians finally returned the painting to the French on December 30, 1913.
I’d laugh but thieves still steal from museums today (http://www.huffingtonpost.com/2011/08/16/stealing-the-spotlight-ar_n_924991.html#s322725). Let’s not forget my posting of the thieves who steal historical items from US Archives. Come on Archivists and Museum Curators, get it together before some treasure is permanently lost or damaged.