It is grammatically incorrect in Italian (like I said, in Italian it sounds like "the our thing"). I'm guessing the American guys who use it don't know the Italian language all that well. The Sicilians would have never said "la" to begin with.
I think the FBI may have actually been the first to use the "la", but I'm not sure why. Nonetheless, the mistake seems to have become permanent.
I just remembered - wasn't it Gotti who was caught on a bug complaining about people mentioning the name "La Cosa Nostra" and that the FBI would jump on just "La"?
Or was that someone else and I'm just thinking of him for "This is gonna be a Cosa Nostra"?
