Gangs of LA

ABC News: Federal Sweep Results in Arrests of 375 Gang Members :

"Since Community Shield was set up last year, Immigration and Customs Enforcement, along with state and local law enforcement agencies, has arrested more than 2,300 suspected gang members, including 51 gang leaders and 922 members of MS-13. MS-13 is believed to have as many as 10,000 members in the United States, who are mostly from El Salvador, Honduras and Guatemala."

Mara Salvatrucha is a major player in the politics of its home country. There are reported to be neighborhoods in some cities and whole small towns where the police fear to go because these are no ordinary criminals. By some accounts, MS-13 began among Salvadoran leftist guerillas who fled to Los Angeles when the Salvadoran government proved itself able to withstand the communist insurgency and only became established in Central America as members were deported from the US - often following incarceration or as an alternative to prosecution for crimes committed here.