Organized crime refers to crime executed by sophisticated criminal associations on a regional, national or international scale. These associations range in size and sophistication from small, loose-knit fellowships that come together to organize a single criminal act to centuries-old organizations, thousands strong, that exercise considerable economic and social influence in their area of operation (the mafia of Sicilia and southern Italy is perhaps the most famous example known to Americans - mafiosi exercized a measure of autonomous governing power in their regions during the first half of the 20th century, often performing important functions of government such as conflict mediation and basic forms of "social security" for the old and infirm).
Organized crime derives its principle source of income from providing services to the public, like any other business organization. The difference is, their services are criminal. Crime organizations do lucrative business in areas such as drug trafficking, prostitution and loan-sharking (offering loans at exorbitant interest rates). Criminal organizations also profit from illegal activities such as cargo theft, kidnapping for ransom, fraud large-scale robbery and demanding "protection payments."
Organized crime is traditionally recognized by its hierarchical structure, with different subgroups operating in designated regions with a relatively high degree of coordination. Ethnicity has traditionally been a dominating factor in organized crime, with different ethnic and national groups, such as the Irish, Russians, Sicilians and Chinese operating independently from one another - and sometimes against one another - in the same cities and regions. In today's globalizing economy, however, ethnicity plays a far less important role in organized crime than it did a century ago.