The situation of garbage disposal in Naples and the monopoly that Camorra (the Napolitan Mafia) acquired upon it is an application of the formula:
What happened there? A couple of decades ago, the Camorra began to invest in garbage disposal companies. Garbage disposal and its treatment are quite expensive, especially when the laws require not to dump dangerous chemicals anywhere in the fields or the rivers. But if you don't care about polluting an entire country, garbage disposal, at the market prices, is very lucrative, because it allows for enormous margins. Using intimidation and corruption to wipe out local competition, and selling its services to industrials to cheaply dispose of their waste, (thus gaining approval from the powerful industry bosses), the Camorra has now transformed the Campania in a wasteland where people are a lot more likely to develop cancers than in other parts of Italy.
Fair competition is part of capitalism, but without an effective judicial power to prevent violence against competitors, the game is biased. Moreover, without a government to edict and guarantee safeguards, protecting its citizens from whatever consequences unrestrained capitalism might have on the environment or on the society, ecological and social catastrophes are bound to happen -- at the very profit of the bad ones.
My formula of course applies as well to the Sicilian Mafia, born at the end of the XIXth century around Palermo; at that time, it took advantage of a very good economical situation in Sicily and of a default of government, Italy being a young kingdom, and Sicily just out of feudalism.
Thus, every time I read on the internets anarcho-capitalism, I mentally translate it into Mafia rule waiting to happen. I'm sure the Honoured Society would be happy to see a libertarian elected in the White House, even if this libertarian is the most honest man on earth. (The Mafia doesn't have political opinions -- it helps whoever will help it.)
(As an aside, Tony Soprano comes from a Napolitan family, and officially works in garbage disposal. The writers were documented...)