Earlier this month thieves made off with a giant Renaissance masterpiece—a 10-foot by six-foot piece painted by Guercino in 1639, and worth over $8 million. Whoever took the painting didn’t have to do much; the security alarm on the church wasn’t working, and according to The Telegraph the church that housed the painting didn’t have the money to get it fixed. 

Once a work of art leaves a museum or church, the chances of getting it back are extraordinarily slim. According to The Art Newspaper, roughly 1.5 percent of the art that is stolen is ever recovered. Once it’s removed from its home, art is as hard to track as a stolen bike or wallet. Tracking your swiped iPhone is easier than tracking a 10-foot by six-foot Renaissance painting, because your iPhone constantly sends signals to the towers around it. Simply click “Find My iPhone” and there it is, location triangulated via GPS. So why don’t museums simply do the same thing? 

Robert Wittman, a former FBI special agent who has recovered over $225 million worth in stolen art (and wrote about it in his book Priceless), says that the technology I’m imagining essentially doesn’t exist. At least not right now. “To do that you’d have to have cell phone sized GPS systems attached to the back of every painting,” he told me. “You’d have to plug in every painting every night.”

Attaching a tracking unit to every painting might sound like a no-brainer, but it’s actually a huge challenge, Wittman explains. You’d need something that has a long battery life that you don’t have to constantly be charging. It would have to be small, small enough to put on the piece without damaging it and small enough to evade detection by thieves. At the same time, it would have to be designed so that if thieves did find it, they could remove it without damaging the art. This mythical unit would have to be powerful enough to transmit from inside boxes and closets and warehouses where burglars might take it, but cheap enough to allow museums to buy thousands of them. “That technology simply doesn’t exist,” Wittman said. 

That’s not to say that people aren’t working on high-tech solutions to art protection. In recent years RFID technology—using electromagnetic fields to identify and track tags on objects—has become more common in museums. In these setups, art is fixed with a small RFID tag that detects if the piece of art moves from its location on the wall or floor. An RFID reader in the building keeps track of these locations. So if someone pulls a painting off a wall, the alarm goes off immediately. But RFID systems only work inside the building. The tracker can only keep tabs on tags within about 230 feet. Once that painting is out the door, it’s electromagnetically invisible. 

And Wittman points out that if the rest of your security isn’t good, RFID isn’t going to help you. “If you have a situation where four individuals go in with machine guns, they don’t care about the RFID. Everybody knows they’re there with the machine guns.” And in situations where thieves are efficient, knowing that a piece of art is moving once the thief has it off the wall isn’t useful. In one case in the Kunsthistorisches Museum in Vienna, a thief broke through a window and a display case and made off with a sculpture known as the Cellini Salt Cellar in just 58 seconds. No alarm response system can react that fast. 

Steve Layne, the founding director of the International Foundation for Cultural Property Protection, says that museums would rather focus on arming the environment than the piece of art itself. “Curators don’t like anything affixed to artwork,” he told me. Instead, Layne says that that most museums put their effort on making sure the art doesn’t leave the museum in the first place. “The primary focus is not on tracking art outside the museum, it’s on tracking it while it’s in the museum,” he said. “The emphasis is on stopping anything from leaving the walls.”

Museums don’t like to disclose what they do and don’t use for security. Neither the Museum of Modern Art nor the American Museum of Natural History would tell me anything about the types of security features they have on individual pieces. 

Preventing thieves from making off with art involves all kinds of high and low tech security systems, from motion detectors to locks on the doors to good old security guards. And both Layne and Wittman say that’s where the future of museum security is going. “Years ago video recorded to a VHS player and that was the end of it,” Layne said. “Now the video systems are computer-based and they can transfer an image anywhere.” Wittman put his money on facial recognition technology. “The people who steal art, they don’t just do it once,” he said. “They just keep doing it, because they become obsessed with these paintings.”

So there probably won’t be a nice, slick “Find my Caravaggio” app in the near future. But there is a place for GPS in art security, Wittman said. When art hits the road, either in a traveling exhibit or to be transported from one museum to another, curator and security professionals will place GPS tracking devices on the trucks and crates. And Wittman sometimes slips a throwaway cell phone into the cab of the truck just in case. “Thieves may be looking for a GPS tracker to pull out but they won’t be looking for a little cell phone under the seat.”