Last Saturday, an elderly man set up a stall near Central Park and sold eight spray-painted canvases for less than one five-hundredth of their true value. The art works were worth more than two hundred and twenty-five thousand dollars, but the man walked away with just four hundred and twenty dollars. Each canvas was an original by the enigmatic British artist Banksy, who was approaching the midpoint of a monthlong residency in New York City. Banksy had asked the man to sell the works on his behalf. For several hours, hundreds of oblivious locals and tourists ignored the quiet salesman, along with the treasure he was hiding in plain sight. The day ended with thirty paintings left unsold. One Banksy aficionado, certain she could distinguish a fake from the real thing, quietly scolded the man for knocking off the artist’s work.