The days when you could walk out of the Louvre with the Mona Lisa under your arm are over. There are all sorts of safeguards now—electric eyes, pressure sensors, lasers, which in the movies at least, must usually be overcome by dangling the thieves from the ceiling. I love art-heist stories. They always pose a question: what’s real and what’s fake? What’s the difference between an original and a copy? They also sketch out over the years not only a change in technology but a change in ethics. Here are five of my favorites. How to Steal a Million–1966 We start with the soufflé, extremely light, and, as you would expect of any film starring Peter O’Toole and Audrey Hepburn. It just oozes charm. Surprisingly, under its candy coating, it also oozes authenticity. The forger(Hugh Griffiths, Hepburn’s papa) has made certain to dig up authentic dirt from Arles to add to his Van Gogh forgery. And it takes only a chip of paint from said forgery undergoing chemical analysis to prove it’s a fake. And it’s the forger’s hubris that places him in danger, which is often the case in real life, where it’s the risk of being discovered that…