Handbook of Organized Crime - Masako Gillette

Organized crime is a category of transnational, national, or local groupings of highly centralized enterprises run by criminals who intend to engage in illegal activity, most commonly for money and profit. Some criminal organizations, such as terrorist groups, are politically motivated. Sometimes criminal organizations force people to do business with them, such as when a gang extorts money from shopkeepers for so-called 'protection'. Gangs may become disciplined enough to be considered organized. A criminal organization or gang can also be referred to as a mafia, mob, or crime syndicate; the network, subculture and community of criminals may be referred to as the underworld. European sociologists (e.g. Diego Gambetta) define the mafia as a type of organized crime group that specializes in the supply of extra-legal protection and quasi law enforcement.