Most gangs operate informally with leadership falling to whomever takes control; others have distinct leadership and are highly structured, which resembles more or less a business or corporation.
some of them known as the Mims, Hectors, Bugles, and Dead Boys.
These gangs often came into conflict with each other.
The Yakuza are among one of the largest criminal organizations in the world.
As of 2005 Colombian Drug Cartels, Mexican Drug Cartels, the Aryan Brotherhood, the Mexican Mafia, the Texas Syndicate, the Black Guerrilla Family, the Nuestra Familia, the Mara Salvatrucha, the Primeiro Comando da Capital, the Irish Mob, the Puerto Rican Mafia, Nuestra familia, the Chinese Triads, the Japanese Yakuza, the Jamaican-British Yardies, the Haitian gang Zoe Pound, and other crime syndicates.
The numerous push factors experienced by at-risk individuals vary situationally, but follow a common theme of the desire for power, respect, money, and protection.
These desires are very influential in attracting individuals to join gangs, and their influence is particularly strong on at-risk youth.According to criminal justice professor John Hagedorn, many of the biggest gangs from Chicago originated from prisons. Charles Illinois Youth Center originated the Conservative Vice Lords and Blackstone Rangers.Although the majority of gang leaders from Chicago are now incarcerated, most of those leaders continue to manage their gangs from within prison.Many of the larger gangs break up into smaller groups, cliques or sub-sets.The cliques typically bring more territory to a gang as they expand and recruit new members.Prison gangs often have several "affiliates" or "chapters" in different state prison systems that branch out due to the movement or transfer of their members.