We have alcohol in the U.S. as an example; It was made illegal; so gangs moved into the import business and made more money than they had before - gangs had turf wars bigger than they had had before.

Moonshiners started making it, and sometimes it created poison.

The police were corrupted where corruptible or killed when they didn't go the gangs ways.

The rich had parties and skirted the enforcement of the law.