Street Art à la Française

What do graffiti tags, stencils, light paintings, collages, murals and urban mosaics have in common? They are all part of an artistic movement that is unique in the history of art and has been a talking point for the past 30 years: street art. While for some their "rise" is a good and important development, for others the relationships that increasing numbers of street artists are cultivating with business, politics and the galleries are a dangerous co-optation.