Automotive
The balls, locally known as bohan yu kara boru, derive their bright hue from the orange paint that fills them. In the event of a theft or robbery, store employees are supposed to fling the balls at the perpetrator. When the balls hit the thief, they will burst, marking him with orange paint and making it easy for the police to identify and apprehend him.
It seems that the balls were developed over two decades ago, as a replacement for throwing eggs at criminals! “At that time, the nation’s highways had a problem with toll evaders, and toll-booth attendants had taken to throwing raw eggs at vehicles that charged through without paying their tolls,” Gordenker wrote. “ While the police appreciated this effort to mark non payers, they felt it was inappropriate to use food for the purpose. So someone came up with pigment-filled balls as an alternative.”
https://www.reddit.com/r/todayilearned/comments/2gaebb/til_japanese_police_fire_paintballs_at_fleeing/#bottom-comments
http://www.odditycentral.com/funny/japans-bizarre-anti-crime-orange-balls-a-unique-way-to-stop-crime.html
http://www.japantimes.co.jp/news/2008/05/20/reference/anti-crime-color-balls/#.WG_qBFMrKM8
