[ohxten]

There is a real-world example against prohibition of narcotics, and that is prohibition of alcohol. It did not work. Billions are spent on the War on Drugs, and yet it's clear that it's easier than ever to get drugs on the street. Posession of marijuana is the number one most committed crime.

The point you made at the end is essentially the argument for why legalization of drugs will solve a lot of problems. Competition will bring in ligitimate sellers (as in the alcohol industry) and get rid of all of the crime that comes from the local dealers who "own" street corners.