Crime and criminals attract attention from nearly everyone. Most people know that homicide, robbery, rape, burglary, kidnapping and drug traﬃcking are crimes, even though they may not be able to deﬁne these crimes with legal precision, but what does it actually mean to say this is ‘criminal behaviour’? Why should some behaviour be criminalised or decriminalised? Why is it legal to smoke tobacco but not marijuana? Why is property inheritance protected by law but not the expropriation of property to achieve the equitable distribution of wealth? Why is it lawful to bet in a licensed gambling establishment (e.g., The Hong Kong Jockey Club and the casino cruise ships based in Hong Kong), but unlawful in other, unlicensed locations? What about littering, abstracting electricity, loitering, and cheating on income taxes? These acts may amount to crimes or oﬀences in Hong Kong even though they may not be generally considered ‘crimes’ – at least, not in the same sense as homicide, robbery, rape, burglary, kidnapping and drug traﬃcking.