Billboards are often ignored. You can walk past a hundred of them in a day and not remember what a single one of them was promoting. We just kind of tune them out. This one in France, however, is a little difficult to ignore. Especially if you’re crossing the street when you’re not paying attention.
The billboard has sensors which monitor for people crossing the road when they’re not supposed to. It plays a loud tire screeching sound making the hapless wanderer believe their life is in danger. It then snaps a photo of the terrified pedestrian and puts it on the billboard. The goal is to raise awareness for the dangers of being a careless pedestrian.