The webcam's public feed, like thousands of others like it, is accessible to anyone who can find its URL with a Google search. At an art gallery thousands of miles away, a tiny Raspberry Pi computer is streaming the video to a monitor while it analyzes the footage with a simple computer vision algorithm. It instantly snitches, flashing, "WOULD YOU LIKE TO REPORT THE JAYWALKER?" on the screen. If you're a visitor at this gallery, you'll face a choice: hit a red button in front of the computer, and it will send a screenshot of the incident in an email to the nearest police precinct, potentially costing her a $42 fine. Or you can let the oblivious lawbreaker go on her way.

This demonstration of surveillance-turned-art, titled "Jaywalking," presents the sort of uncomfortably easy privacy invasion that Dries Depoorter has made his trademark. The 25-year-old Belgian artist has a talent for assembling widely accessible images and video streams into exhibits that feel provocatively intrusive. And he hopes they'll spark his audience to consider the very real possibilities of using public data to invade personal privacy—or at least what we once believed to be private.