In Japan they have bike theft sorted with mandatory registration with the local police force. A sticker on the bike and a corresponding bit of paper in the wallet provides proof of ownership, which may be requested by police at any time.

This costs money to administer but it means that nobody in Japan needs to overly worry about their bicycle being stolen. Huge locks are not needed, nor is GPS tracking or third party registration schemes.

The idea of getting a 'hack bike' that looks undesirable is often touted as a solution to cycle theft in the West. However, thieves just want money, so the 'hack bike' that can be easily sold trumps the hard-to-sell expensive bike if money is needed now, for tonight's high. More money can be tomorrow's problem.