Mafia humour would be misunderstood by most

I like this plate, problem is, if you put this on your car, you could never sure how many people would take it seriously, and the next thing you know you’ve got Mr. Police Man knocking on your door, or the real mafia...Why is it that the funniest things offend/confuse the most people? It simply isn’t fair for those of us with a sense of humour.