Originally posted by Sonny Forelli:
I have read the word originated from a kidnapping in sicily in the 1800's. When a womens son was kidnapped by a local gang she ran out onto the streets screaming "La Mafia!" Which was a form of the italian word for "mischief"... cant remember were this is from
Maybe it's a version of the story from the site provided by Lavinia?
Former U.S. mob don Joseph Bonanno provided an origin that was a confused reference to the Sicilian Vespers, a patriotic uprising in Sicily against the French in 1282. Bonnano claimed that French soldiers had violated a Sicilan girl. The girl's distraught mother ran through the streets of Palermo crying "ma fia" ("my daughter"), causing the young men of Palermo to kill the French in response.