The question that every pothead has at some time asked: why is marijuana illegal when the more damaging tobacco and alcohol are not? Customers of the brothers arrested for having 600 cannabis plants in their Yuen Long house last week may be wondering that at this very moment.
Alcohol is outlawed in many countries, of course, and, along with widely banned drugs, tobacco and coffee have been targeted by prohibition lobbies at some time or other. While there are health implications associated with taking anything in excess (even vitamin A can be harmful in too great a quantity), religious intolerance, profit motives and racism have all played a part in these campaigns against the enjoyment of the individual. That some recreational substances are legal and others not is essentially down to twists of fate over many decades - and there is no telling which will be acceptable and which will be frowned upon 100 years from now.
As authorities around the world - from California, where the Regulate, Control and Tax Cannabis Act was tabled last year, to Portugal, which decriminalised drug possession for personal use in 2001 - grapple with the issues, their police officers will tell you - perhaps off record - that they would rather have to deal with a person who is stoned than one who is drunk, the latter being much more likely to throw punches.
Perhaps the dramatic drop in cannabis seizures in Hong Kong last year reflects a shift in perception even on our unenlightened shores.