Saying stuff like “Greek Mafia†or “Jamaican Mafia†to describe ethnic Greek, Jamaican, etc... underworld is as laughable as saying “Sicilian Yakuza†to describe Palermo’s vice scene.
It's interesting by the way, whether other countries do in fact use their own terms to describe foreign organized crime, like whether the Japanese use "Sicilian Yakuza" when talking about the Cosa Nostra etc