Today's mafia is organized into "families" with the main idea being to make money. They do things like money laundering to turn ilegal money into legitimate money. Mafiosi of today try to make contacts, not enemies, if anyone presents them with any challenges, they are brutally erased.
The Mafia originated in Sicily during the 1700's because it is the largest island in the Mediterranean Sea. Sicilian peasants were little more than slave labor to their foreign overlords. The Mafia "vendetta" was the Sicilian form of justice.