The Mafia controlled most gay bars due to their illegal status, and extracted a monetary premium from the gay community. This recognized both the legal risk the Mob was taking and the near-monopoly status it enjoyed. After all, where else were gay folks going to meet? There were often high cover charges and minimum drink requirements. Moreover, gay men were at risk of blackmail from their Mob overlords
https://www.vice.com/en_us/article/gqmym3/how-the-mafia-once...
I had never heard this before, but it is easy enough to find it. There are at least a couple of other articles that readily came up.