Pope Francis has declared a sort of holy war on the Mafia. And it's not unreasonable to believe that the Mafia may fight back.

On Saturday, the pope traveled to Calabria, the heartland of one of Italy's biggest organized crime enterprises, the 'Ndrangheta, and, in front of a crowd of more than 100,000, blasted the 'Ndrangheta as example of "the adoration of evil and contempt of the common good." Then he dropped the hammer:

Those who in their lives follow this path of evil, as mafiosi do, are not in communion with God. They are excommunicated. [Pope Francis]

This is a big deal. Southern Italy's mobsters are a pietistic bunch — an overwhelming majority are active Catholics, and religious celebration is an important part of their public image and local legitimacy.

"During the making of a recent documentary for Italian television, I visited many of the fortified bunkers that 'Ndrangheta bosses have built in case they need to go to ground," Mafia researcher John Dickie told CNN last November.