[midoridensha]

It's still like that here in Japan: bikes are all registered with the police and have stickers with their registration numbers. When they're stolen (which is usually done by drunk people wanting a quick ride home, or teenagers using them for joyrides) and recovered, the police will bring the bike back to the registered owner. Usually, the best way to avoid theft is to simply lock your bike's rear wheel so it can't be ridden away easily.