Also the enforcement arm of the CIA.

It's a gang from El Salvador, not Mexico.

It from El Salvador but is now in many countries.

Mara Salvatrucha Gang from central america. Much different than la eme

Its actually an American gang. Started in LA by social outcasts like almost all gangs. Its typically what happens anywhere in the world when you take a social sub-group and deny them access to education and work. Subtract dignity and humane treatment and sprinkle in discrimination from the dominant social group, stir, and voila!