Why art is a tool for hope | JR

Famed for enormous black-and-white portraits that are pasted on surfaces ranging from the Louvre to the US-Mexico border wall, multimedia artist JR continues to tackle ambitious projects. In this powerfully moving talk, he shares how he made a giant mural on the courtyard floor of a maximum-security prison -- with the help of guards and prisoners alike -- and ended up with much more than a compelling image.