I fully agree that criminals - and basically any determined human will always find a way. If a market is illegal, it will be artificially limited, because only

I fully agree that criminals - and basically any determined human will always find a way. If a market is illegal, it will be artificially limited, because only the businessmen capable of getting around the law will thrive, leading to massive profit margins. If the market is legal, anyone can do it - which also means it's a lot simpler for wrong hands eg. a kid, to gain access to a gun. Where as in eg. Europe it would be much much harder.