Apparently when Al Capone didn't have a machine gun in his hands he was quite the humanitarian. He opened soup kitchens and when one of his family became ill from drinking milk that was off, rather than shoot the supplier in cold blood he looked further into the whole milk distribution racket.
It turns out there was some shady dealings and very little regulation into the supply, storage and delivery of milk. With prohibition ending and a fleet of trucks at his disposal he lobbied authorities to set USE BY: dates for milk and entered the milk business.
You can read all about it at carboncountrymagazine.com - there's an interesting twist to the story.