Pictured above (via Oddity Central) is the checkout counter at a Japanese convenience store, seen from the view of the cashier. There’s a computer terminal that acts as a register, various papers, and two baseballs which, for some reason, are glowing orange. The baseballs are pretty common at similar stores, but they’re not for sale.

They’re for throwing at bad guys.

The balls are known as “bohan ya kara boru,” or “anti-crime color balls.” The idea behind them is simple: if a patron decides to instead be a shoplifter, the store employees can fight back by firing one of these balls at the malfeasor. The balls are hollow spheres filled with orange paint. They’re rather fragile, too; as seen in this video, even a dropped anti-crime ball can cause a great deal of mess. But that’s by design.

When a thrown ball hits a person or a surface, it explodes, splattering a rather wide area in fluorescent orange. The goal is to mark the criminal so that authorities can catch the wrongdoer shortly thereafter. Garish orange-stained clothes aren’t something that one typically sports as part of his or her normal ensemble, making it easy for authorities to pick a fleeing shoplifter out of a crowd.  So, if a shopkeeper throws one of these balls at a criminal, he or she need not hit the target — the clerk only needs to throw the ball so that the bad guy is in the splash zone.

The innovation is an off-shoot of vigilantism from the 1980s. At the time, according to Cultural Fact of the Day, many drivers had a habit of passing through toll plazas on Japanese highways without paying the toll. In response, toll booth operators decided pelt to the scofflaws’ cars with raw eggs. While the eggs didn’t stop the non-paying drivers, they did mark the car as one being driven by a toll avoider. The anti-crime color balls are the next-generation application of that same principle.

That’s the idea, at least. But the balls, as the Japan Times reported in 2008, aren’t thrown at criminals all that often. During the first half of 2007, per the Times, these orange balls were present at the scene of 197 store robberies (out of 230 surveyed) but were only used seven times. That said, local law enforcement encourages stores carrying a lot of cash to also have these orange balls displayed prominently at the register. Why? Because the color balls still serve as a deterrent — the threat of even an approximately 3.5% chance of being inked may prevent a crime before it happens.