We are having serious problems in San Diego and Riverside counties in Southern California with non-permitted growers. Many are linked to Mexican cartels. Many tend to operate with pirated power and water. And all of the illegal growers have been bad for the local environment because of improper and excessive use of pesticides and fertilizers.
An illegal grower recently stood up a greenhouse, made of stolen materials, on a neighbor's property. When he stumbled onto the site, they threatened him and shot at him. The Sherrif's department would not respond to a 911 call so we called the local fire marshall. When fire people got threatened, the sherrif's dept decided they would respond. The county DA has not charge anyone with anything. It cost him several thousand USD to clean up the site.
We need to de-criminalize cannabis use. We need to be much more thoughtful about legalizing cannabis.