Free markets do not fall prey to these robber barons. Such people need political protection. Subsidies and regulatory capture are necessary to such schemes.
Mafiosos do not enjoy subsidies and are awarded no political protection, and yet, they thrive in unregulated (lawless) areas of the planet.
They thrive because over-regulation or outright prohibition has created a black market. Their violence is a mirror of the government's violence, because government is itself a mafia writ large.
Mafiosos thrive in 100% lawless environments like remote refugee camps and abandoned war-torn no-mans-land.
MOBSTER ETHICS = NATURAL LAW