Back in 2003, original prankster-artist Banksy bought an oil painting at a street market, altered it and glued it to the wall of London’s Tate Britain gallery. Next to it, he placed a sign: "This new acquisition is a beautiful example of the neo post-idiotic style. Little is known about Banksy whose work is inspired by cannabis resin and daytime television." The painting stayed up for several hours before crashing to the floor, leading to its discovery.