Al Capone had only one offspring, a son named Albert Francis Capone, "Sonny

Question:

Al Capone had only one offspring, a son named Albert Francis Capone, "Sonny". Sonny had four daughters.

Sonny later changed his name to Albert Francis. What became of Al Capones four grand daughters and any great or great great grandchildren?

Best Answer - Chosen by Asker: http://en.wikipedia.org/wiki/al_capone...
Not exactly what you asked, but this article contains specifics about his parents and siblings. There is a file on rootsweb, indicating that his grandchildren were probably all born in the 1940s or later, and thus would presumably be still alive. For obvious reasons, those kids may well prefer to keep their details private.
Just as an aside... blacksheep ancestors is an email list specifically for persons who descend from notorious persons, such as criminals. Last time I looked, that was hosted over at rootsweb's mailing list, and archives are searchable. If any of his family chose to be public, that might be where you would find them.