The changing economic landscape of Sicily shifted the Mafia 's power base from rural to the urban areas . The Minister of Agriculture – a communist – pushed for reforms in which peasants were to get larger shares of produce , be allowed to form cooperatives and take over badly used land , and remove the system by which leaseholders ( known as '' " gabelloti " '' ) could rent land from landowners for their own short-term use . Owners of especially large estates were to be forced to sell off some of their land . The Mafia had connections to many landowners and murdered many socialist reformers . The most notorious attack was the Portella della Ginestra massacre , when 11 people were killed and 33 wounded during May Day celebrations on May 1 , 1947 . The bloodbath was perpetrated by bandit Salvatore Giuliano who was possibly backed by local Mafia bosses . In the end , though , they were unable to stop the process , and many landowners chose to sell their land to mafiosi , who offered more money than the government
Portella della Ginestra massacre
Portella della Ginestra massacre
Sicilian Mafia