The 18th Street Gang, also known as “Barrio 18” and sometimes simply referred to as the M-18, is one of the largest youth gangs in the Western Hemisphere. Like its better known rival, Mara Salvatrucha (MS-13), the M-18 has cells operating from Central American to Canada, including the United States. Furthermore, with thousands of other members in countries spanning hundreds of miles, and economic interests in a number of different illicit activities, M-18 is one of the more significant emerging criminal threats in the region. Still, its unity across borders, even within cities, is questioned.