The term gang conjures up a number of sinister specters in the 21st century. As the most prominent examples of gangs that exhibit organized crime attributes, this chapter focuses on outlaw motorcycle gangs (OMGs), urban street gangs, and prison gangs. In 2011 the United States (US) State Department and the Department of Homeland Security added the major OMGs to a list of criminal organizations that includes the Mafia, Chinese triads, and the Japanese yakuza. According to one 2013 gang survey, the vast majority of gang members in the US are street gang members, followed by prison gang members, and then OMG members. The continued demographic changes resulting from globalization, urbanization and immigration patterns, combined with the ever-changing demands of illegal markets have an impact on all forms of gang criminality, especially those based on race and ethnicity.