They got rid of that particular problem (gangs and maryjane) in Holland by simply letting everyone grow up to 5 plants of their own. Killed the demand overnight, price dropped to zero, gangs moved on to the good stuff like prostitution, bootleg liquor, identity theft, hard drugs, bribing politicians etc. There'll always be something illegal, and it will always be a big moneymaker.
It has been mentioned more than once that if the hells angels were smart (and there's absolutely no reason to not assume they are) they are lobbying (isn't that the polite word for bribery?) very hard to keep the laws against possession of mary jane on the books.
Stan
This is so funny, the BBC site has a story of a new law in the Netherlands banning the use of tobacco (I think just in public places) however the cafes that serve marijuana will be still allowed to serve and sell joints,
but only if they contain no harmful tobacco Gotta love it
Stan