Members of the Mafia are depicted in popular culture as wearing pinky rings on either hand to signify that they have connections to the mob. There is no cultural significance concerning whether the ring is worn on the right or the left hand.
Self-made men in the American Mafia wear pinky rings as a way to provide their associates with something to help with their funeral expenses, should they be killed while on Mafia business. Confidence tricksters and other criminals also wear pinky rings for similar reasons. Television shows such as The Sopranos have popularized the association of pinky rings with organized crime in the minds of the public.