Like it or not, "street art" is becoming a mainstream phenomenon in America. Due in part to the high profile of artists like Shepard Fairey and Banksy, and the pioneering philosophy of museum directors like MoCA's Jeffrey Deitch—who has planned a large-scale street art show for 2011—what was once considered urban blight is now being recognized as a legitimate artistic medium.

While the basic legal issues facing street artists are relatively straightforward—painting a building/sign you don't own can lead to civil and criminal liability—the more nuanced legal issues concern copyright and ownership. If Banksy does this to my warehouse, can I sell my wall to a museum? Can I make T-shirts or take photos? Can I paint over it? While these types of questions are probably anathema to most street artists, they are great food-for-thought for those on art's "business side" and, most of all, us lawyers.