I'm aware, and have used, this practice in Oakland, CA, Los Angeles, SF, Boston, Philadelphia, Seattle and Portland OR. One reason I keep a small amount of cash around - just for the vig.
It's not just money you pay to shady people. If he charged you $5 for parking, but allowed you to pay when you came back, but it would be $10 instead, you could say the additional $5 was the vig as that represents a 100% interest on a short term loan.
You know that what you said isn’t true. Or you are really badly informed.