Jeffrey Deitch’s bold claim, that graffiti is “arguably the most influential art movement since Pop,” was meant to rile people up. The provocative statement was found in the exhibition catalogue to the ambitious Art in the Streets exhibit at the Museum of Contemporary Art, Los Angeles, in 2011. Graffiti and street art have been shown in museums and galleries before, but Art in the Streets was the very first attempt at a historical retrospective and survey of this wide-ranging, ill-defined art movement.