MEAGHAN GOLDSTEIN—On October 5, 2018, right after the gavel fell accepting a $1.4 million telephone bid, someone in the crowd at Sotheby’s (London) triggered a remote-control shredder encased in the framing of the Banksy painting up for auction. The spray-painted canvas Girl with Balloon passed partway through the hidden shredder before stopping—half safely ensconced in […]