The FBI estimates the size of the four IOC groups to be approximately 25,000 members and 250,000 affiliates worldwide. There are more than 3,000 members and affiliates in the United States scattered mostly throughout the major cities in the Northeast, the Midwest, California, and the South. However, their largest presence centers around Boston, New York, northern New Jersey, and Philadelphia. Their criminal activities are international with members and affiliates in Canada, South America, Australia, and parts of Europe. These organizations are also known to collaborate with other international organized crime groups from all over the world. The Italian gangs (especially the Sicilian Mafia) have also connections with the Corsican gangs. This collaboration were mostly important during the French Connection era.