The current conflict between police and gangs over alcohol
The Great Beer War is the currently ongoing conflict in Chicago with police cracking down hard on liquor, alcohol and in particular bootlegging, as a result of Prohibition
Where several criminal gangs in Chicago are making big bucks by smuggling in alcohol, both for local consumption and to be sold to other cities, the Chicago Police Department is cracking down hard after Mayor Dever decided that their internal conflicts were a problem for the city.
The Great Beer War has already claimed douzens of lives and while public alcohol use has mostly disappeared as a result of the crackdown, the war is still very much ongoing as the underground of speak-easies and gang activity has only grown.