In a world where Banksy street-pieces — essentially, illegally created public art — cut from buildings can generate hundreds of thousands of dollars, proprietary domain is a hot-button issue. Legally, according to attorney Eric Baum, who represented artists in litigation involving the 5 Pointz mural space in Long Island City, “The owner of the building can sell [or keep] the artwork.” And, he adds, the property owner can also destroy it.