"The Bloods was initially formed to provide members protection from the Crips." (https://en.wikipedia.org/wiki/Bloods)
"Originally, [MS-13] was set up to protect Salvadoran immigrants from other gangs in the Los Angeles area." (https://en.wikipedia.org/wiki/MS-13)
"The inmates who formed the Nuestra Familia gang banded together to protect themselves from the Mexican Mafia" (https://en.wikipedia.org/wiki/Nuestra_Familia)
"The [Los Viagras cartel] began operating as a self-defense force (grupos de autodefensa comunitaria) in 2014." (https://en.wikipedia.org/wiki/Los_Viagras)