Ever reached into your pocket to find your phone had been snatched? Dutch film student and former iPhone owner Anthony van der Meer experienced that awful feeling first-hand while having lunch in Amsterdam. Unsatisfied with the response from the Amsterdam police, who register an average of 300 stolen phones per week, Meer decided to find out what kind of person steals a phone. He downloaded DIY security software on a decoy Android phone, intentionally got the phone stolen, and was able to spy on his thief for weeks. He recorded the ups and downs of his covert investigation and turned it into a 22-minute documentary called Find My Phone.

Meer preloaded the decoy device with an anti-theft application called Cerberus, which allows the owner of the device to access any file on the phone remotely, as well as discretely activate the phone’s camera and microphone. Meer and his friends were able to navigate the technicalities of surveilling the thief with relative ease. They even snapped a close-up of the guy’s face. The hard part, it turns out, was getting the preloaded phone stolen in the first place. It took Meer four days to get his device pilfered in a city with high rates of theft because concerned citizens kept coming to his rescue.

The documentary offers a valuable lesson in cyber security (if not also an ethically gray commentary on surveillance). Our smartphones often contain our most sensitive data, including photographs, emails, and bank information, that can be exploited by thieves in any number of harmful ways. Check out Meer’s entertaining and sometimes disturbing documentary to learn what you can do to protect your information.