The Civil Border Patrol is a group featured in Grand Theft Auto V.
Background
The Civil Border Patrol are a civilian operated paramilitary group that operates in Blaine County and aims to "protect" America from "dangerous" illegal immigrants. The group consists exclusively of two members: Joe, a paranoid southern man who despises immigrants; and Joe's best friend, Josef, a cold, violent Russian immigrant who doesn't speak barely any English.
The group makes weekly trips across Blaine County to find, capture and report people of Mexican heritage, most of whom appear to be legal citizens of the US and thus cannot be deported, though this does not deter Joe and Josef from trying. The CBP almost exclusively uses Stun Guns as their weapons, intending to capture illegal immigrants alive since - as Joe puts it - the Civil Border Patrol are "civilized people".
Role in GTA V
The CBP play a central role in the Minute Men series of Strangers and Freaks missions. Trevor Philips first meets Joe and Josef when they are spying on a parked van in a parking lot in Sandy Shores. After Josef berates Trevor for not understanding English - despite speaking Russian - and for not having his papers, they introduce their group and it aims. Joe, realizing Trevor is a fellow "patriot", offers to pay Trevor for his services in capturing immigrants. The trio go to the Yellow Jack Inn and chase after a group of mariachi musicians that had been playing there, eventually crashing their car and taking them captive.
Later on, Trevor stumbles into the CBP again and once more gets paid to assist them in rounding up Mexicans. After re-capturing Manuel, one of the mariachi singers who is seen fleeing on an ATV immediately after the trio meet, they travel to the local cement factory and chase after a pair of workers who are leaving on their motorcycles.
Following this, Joe and Josef tell Trevor to leave, and then take Manuel and the other two workers to the police to deport them. Here, they discover that all three of them are legal citizens and thus cannot be deported.
A few days later, Manuel finds Trevor in Paleto Bay and tells him that the CBP have been harassing several legal Mexican-Americans in Blaine County for years and by helping them, even if it was for money, he was only encouraging them to continue their racist activities. After being threatened at gunpoint, an indignant Manuel scolds Trevor for his actions and informs him that the CBP are in a nearby farm, in case he desires to "make things right". Trevor, guilty and infuriated, travels down to the farm and finds Joe and Josef attacking a family of Mexican descent that lives there, prompting him to kill them both in a fit of rage.