More than that... Bars are great targets for mafia types. My grandfather ran a bar in NYC in the 40s-70s... Any business concession other than the phone company was mob controlled. The cigarette machine, jukebox, tap cleaner, pinball, ice was mob controlled.
When you hit the nadir of NYC in the 70s, it was difficult to make sales tax payments with all of the leeches attached to the business.
Blackmail probably existed but it was just a great opportunity to sell drugs and booze in illegal bars.