There are no violent gangs fighting over aspirin territories. There are no violent gangs fighting over whisky territories or computer territories or anything else that's legal. There are only criminal gangs fighting over territories covering drugs, gambling, prostitution, and other victimless crimes. Making a non-violent activity a crime creates a black market, which attracts criminals and gangs, which turns what was once a relatively harmless activity affecting a small group of people into a widespread epidemic of drug use and gang warfare.