The Altruists are a cult living on Mount Chiliad.
The Altruist Cult is a malevolent religion comprised entirely of old men from the baby boom generation that believe all other generations after them are the cause of all problems in the world and with a distaste for technology, even though some members use cars, and the entire group maintains a website.
Members can be seen walking around half naked, some fully naked, with their penises on show. The cult makes their home in a small, but functional fortified village in the Chiliad Mountain State Wilderness, with numerous buildings painted with their livery.
Events of GTA V
After the mission Nervous Ron, a text from Ron mentions the cult requesting "lost souls" in exchange for cash. It is implied that the cult are cannibals, as Ron says that they "just want them for dinner" and are obsessed with "young blood".
Trevor can take certain random event characters to their camp for a reward, where they are most likely killed for their flesh. Trevor likely has a history of doing this as he refers to the cult as his "friends in the mountains".
After four people are delivered, an event is triggered in which Trevor is taken into the camp at gunpoint. He must then fight his way out of the compound by killing all of the cult members. There are five briefcases around the camp which each contain $25,000 (totalling $125,000), as well as an RPG, an assault shotgun, a baseball bat and body armor as well as health on the gate watch tower - all of which (except the money) respawn.
A random event can be triggered somewhere in the desert or countryside, where two cult members attempt to attack a woman.
The cult's website, accessible with the in-game web browser, is "www.altruistsunite.com". One can find the logo of the cult there, along with a string of morse code. The morse code translates to-
[1st Cyan Block]
THE INDUSTRIAL REVOLUTION HAS BEEN A DISASTER TO THE STABILITY OF THE HUMAN RACE.
ALMOST ALL WOULD AGREE THAT CONTINUED FOCUS ON THE SUPERIORITY OF THE SUB 40 YOUNGER GENERATION WILL RESULT IN THE CATASTROPHIC AND TRAGIC END TO OUR CIVILIZATION.
MAN IS A NOCTURNAL ANIMAL BY NATURE.
THOSE WHO EXIST IN THE INDUSTRIAL-TECHNOLOGICAL SOCIETY, BATHING IN SUNLIGHT AND ELECTRONICS, SUFFER FROM PSYCHOLOGICAL PROBLEMS.
HYPERVITAMINOSIS D CAUSES ABNORMALLY HIGH CONCENTRATIONS OF CALCIUM, WHICH CAN CAUSE HARM TO THE HEART, KIDNEYS AND BONES. TOXIC CONCENTRATIONS ARE A DIRECT RESULT OF EXPOSURE TO THE SUN.
CROWDING CAUSES STRESS AND AGGRESSION.
PRIMITIVE SOCIETIES, ONES WHERE CLOTHES AND TOOLS OF THE INDUSTRIAL REVOLUTION WERE NOT NEEDED, PROVIDED A STABLE FRAMEWORK FOR THE FUNCTION OF SOCIETY.
ONE CANNOT COMPLAIN ABOUT THE DECAY OF TRADITIONAL VALUES YET EMBRACE TECHNOLOGY.
A MAN AS AN INDIVIDUAL, WORKING WITH AN AUTONOMOUS GROUP OF INDIVIDUALS, ALL OF WHOM ARE NAKED IN SPIRIT AND IN THE CLOTH, REMAINS HEALTHY TO HIMSELF AND OTHERS.
SUB 40S ONLY EXIST AS SUBSISTENCE TO THE ALTRUISTIC MAN AND GAINS LIFE FROM CONSUMING THEM.
BAN CLOTHES. BAN LIES. BAN DECEIT. EAT OF THE FLESH. DRINK OF THE BLOOD. WE SHALL BE FREE ONCE MORE. BECAUSE WE KNOW. ALTRUISM. THE GREATEST GOOD, FOR THE GREATEST GENERATION. WE SHALL BOOM AGAIN.