|Divinely-translated articles about|
|Restoration by interpretation|
|Even by study and also by faith|
|Following the needle of the Liahona|
|Drink the Kool-Aid|
|But you WANT to stay!|
“”My God, what have I done?
|—Reportedly the last words of Warren Jeffs' father Rulon, looking at Warren.|
Fundamentalist Mormonism (the best known group of which is the Fundamentalist Church of Jesus Christ of Latter-Day Saints, FLDS) consists of splinter groups from Mormonism who have usually split away from the main church due to their continued practice of polygamy. These smallish groups often live in self-imposed isolated communities and often end up taking on the nature of cults due to their continued isolation, beliefs and practices that are not generally accepted by the mainstream community or are not legal (such as polygamy and underage marriages) and persecution complex. The FLDS controls members through several practices, one of which is forced disconnection from those who leave, including immediate family members. Members are directed to "shun the apostates", and when a male head of household leaves or is excommunicated, his wives and family, including children, are "assigned" to someone else.
FLDS headed by Warren Jeffs
The largest, and generally most newsworthy, is the Fundamentalist Church of Jesus Christ of Latter-day Saints (FLDS) led by Warren Jeffs, who in August 2011 was sentenced on federal charges of arranging forced marriages of underage girls in his church to older men, for fathering a child with a 15-year old girl,, and sexual abuse inflicted on his 12-year old child bride.. Amazingly, although Jeffs has been sentenced to life in prison, he still continues to lead the church from his prison cell, by faithful followers who consider him their Prophet.
The FLDS as headed by Warren Jeffs is based in three inclusive and isolated communities: the largest includes the conjoining towns of Hilldale, Utah and Colorado City, Arizona (also known to locals as "Short
Bus Creek") on the Utah-Arizona border, with a population in the tens of thousands. The YFZ ranch in Eldorado, Texas is a newer compound built in the past 10 years where their temple is located (population several hundred). In Hilldale/Colorado City and Bountiful (see below), the FLDS is the main — or only — presence in those towns; until recently in Hilldale and Colorado City it was impossible to buy any real estate because it was all owned by an FLDS-controlled trust (FLDS members practice holding all goods in common, a practice abandoned by the main LDS church very early in its history). In theory, properties and goods are owned by all church members; in practice, the church leaders control these assets. In Hilldale/Colorado City, non-FLDS residents have been routinely persecuted by FLDS-controlled local law enforcement.
Canada and Mexico
There is a large group of Mormon Fundamentalists living in Bountiful, British Columbia and small communities within Mexico. They were one of the many groups of polygamists dispatched by the main Latter-Day Saints church to Mexico and Canada to continue to practice polygamy after the church renounced it, due to pressure by the US government. Many of the Mexican groups have returned to the US due to the Mexican Revolution, although the settlement in Bountiful is firmly established, and they mainly send wives down to Colorado Springs to be married off to FLDS members.
Their presence in Eldorado, Texas is on the 1700 acre "YFZ" ("Yearning for Zion") Ranch outside of town. On April 4, 2008, Texas Child Protective Services began removing a reported 183 women and children from the YFZ Ranch and placing them in protective custody, and on April 5 a standoff ensued when authorities attempted to enter the church's secretive temple.
Said standoff turned out to be a major embarrassment for the Texas authorities; after the original tip turned out to be a possible prank by a woman with a history of false tips, TXCPS botched the initial raid and subsequent investigation and wound up being forced to return most of the children (some of whom were actually adults mistaken for children). That's some fine police work there, gentlemen.
This also resulted in more public sympathy for the cult, as the public had little understanding of the realities of life for women and girls in it, and only saw photos of children being ripped out of mothers' arms. This in turn helped perpetuate the FLDS abusive culture towards women, facets of which include little to no schooling allowed past 8th grade, insistence upon female subservience, limited "choice" in all matters for women, including manner of dress, length of hair and hairstyle allowed, activities outside the home, choice of spouse, and the practice of assigned marriages of underage girls (starting at age 13) to (often) much older men who already have multiple wives. (FLDS Leader Warren Jeffs, among his multitude of wives, also married a 12-year old.)
Of the FLDS sects not ruled by Warren Jeffs, one of the better known is a long-established group (originally called "The Work") founded by the LeBaron family, that resides in Mexico. 
Apostolic United Brethren (AUB)
One of the few fundamentalist groups that doesn't outright reject the authority of the mainstream LDS church. Rather, the AUB is somewhat of a restorationist sect, believing that they need to protect the original 19th-century doctrines that the mainstream church has abandoned, e.g. polygamy (though not all AUB participate), communalism, and the Adam–God doctrine. TLC's Sister Wives stars a family that was once part of this sect.
Confederate Nations of Israel
A significant, but unusual, group is the Confederate Nations of Israel based in Big Water, Utah, organized in 1977 and led by Alex Joseph until his death in 1998. Big Water was originally known as Glen Canyon City (and made famous in Edward Abbey's The Monkey Wrench Gang) until Alex Joseph and his polygamist followers moved in and it became Big Water. In 1986, Joseph, who was also Big Water's mayor, and the entire city council changed their party registration en masse from Republican to Libertarian. Unlike most fundamentalist Mormon groups, the Confederate Nations of Israel has held to a very live-and-let-live approach: polygamy is optional, and openly gay members are accepted. Alex Joseph made a movie about himself, Alex Joseph and His Wives, and had his occupation listed on his death certificate as "pirate". The current mayor of Big Water is a member of this group and the first openly gay mayor in Utah.
Another significant group is the Kingston Clan, also known as "The Order" and officially the Latter Day Church of Christ, with about 2000 members scattered throughout Utah. They own a large number of real estate holdings and businesses through a cooperative company, the Davis County Cooperative Society.
In addition to exhibiting all the cult-like behavior associated with fundamentalist Mormon sects, this group also appears to be an organized crime family. In 2018, United States authorities arrested Jacob Kingston, leader of the sect, and several family members and business associates. They are accused of defrauding the United States Government out of half a billion dollars by abusing biofuel subsidies.
There are also the lone cranks, usually excommunicated from the main LDS church once they enter into a polygamous marriage, and occasionally one of them pickets the Mormon temple in Salt Lake City with "plural marriage is necessary for salvation" and like signs, much to the guffaws and amusement of tourists.
A central principle or tenet of the Mormon fundamentalist groups, including the FLDS, is polygamy, defined for their purposes as the male head of household having multiple wives (which is specifically polygyny).
When Joseph Smith originally founded the church in the early 1820s single spouse marriage was the standard. From the Book of Mormon: the Lord told the prophet Jacob "for there shall not any man among you have save it be one wife: and concubines he shall have none" (Jacob 2:27-30).
Then, in 1890 the LDS President, Wilford Woodruff, outlawed polygamy. Woodruff claimed to have received a revelation that the leaders of the Church should cease teaching the practice of plural marriage and issued "Official Declaration 1". This cleared the way for Utah to become a state in 1896. Since then, polygamy has not been practiced by most Mormons, the exception being by the members of the few "fundamentalist" groups, who refused to accept a law that they believed went against God's word. They started splinter groups of fundamentalists, including the FLDS, that still to this day practice polygamy.
FLDS Mormons believe that multiple spouses married in Mormon temples will be "sealed" to each other and their offspring as functioning family units even in the afterlife. 
So why not leave the polygamists alone to live their lives as they see fit?
Because there are children involved
Many people believe that while consenting adults may decide to live their lives as they see fit, society as a whole has an obligation to protect children from abuses. It has been documented that basic schooling and education is routinely denied to children in the FLDS; there are cases of human rights violations, and sexual abuses of both boys and girls. In the FLDS, children are indoctrinated into a pattern of thought from birth and told that to question the beliefs is sinful. Questioning also brings punishment. Their minds are therefore trained not to question, and the power of free thought is shut down. This leaves them ill-equipped to function outside of their limited community. The FLDS also violates child labor laws, forcing young children to work long hours of manual labor without pay.
Human rights abuses
The FLDS strictly controls all aspects of women's lives, from manner of dress, to who can marry, and may arbitrarily "re-assign" them to a different spouse. Women are taught to be subservient to men, and are valued only for the number of children they have, and how well they follow the doctrines. Mothers are not allowed to take their children with them if they leave the FLDS, as the children "belong to the priesthood".
See the "Birth Defects Prevalent in the FLDS" section below for details: Due to many years of intermarriage among family members, the FLDS has the highest known rate of a rare genetic disorder called "fumarase deficiency" that causes severe birth defects. In addition to this issue, since the rulers of the FLDS control most of the money, property, and other assets (homes and land are owned by the church, not by individual members), the average FLDS family, with children numbering in double digits, has a very poor standard of living, causing many polygamist families to be reliant on social services (welfare payments), including cash aid, food stamps, and government-provided medical care. Far from seeking to be self-supporting, they call accepting these payments "bleeding the beast". A dozen FLDS leaders are currently facing trial for food stamp fraud and money laundering 
Birth defects prevalent in the FLDS
The communities of Hildale, Utah, and Colorado City, Arizona have the highest prevalence of known fumarase deficiency cases. In this disorder, brain cells fail to receive enough fuel to grow, multiply and function properly because of a missing enzyme needed to generate energy from food, causing serious intellectual disability and muscle control problems.
Medical professionals discovered fumarase deficiency was occurring in the greatest concentration in the world among the fundamentalist Mormon polygamists of northern Arizona and southern Utah, and that the recessive gene that triggers the disease was rapidly spreading to thousands of individuals living in the community because of decades of inbreeding.
Boys in, and out, of the group
One might think that having as many wives as they desire sounds like a dream for men… but no. If boys and girls are born at roughly a 50/50 ratio (it's actually 52/48 B/G) and the elder men take multiple wives, how are there enough women to go around? The answer is, there aren't. There simply are not enough females for all the men to have wives. This results in many boys being cast out of the church when they reach their teens (females are always retained) and told they are no longer "worthy of the priesthood". Of course, if you are going to abandon the boys anyway, there is no incentive to avoid things like child labor.
According to Brent Jeffs (nephew of Church Leader Warren Jeffs) in his book Lost Boy, there are huge groups of ex-communicated "Lost boys" who have been kicked out of the FLDS.  These boys are under-educated and ill-prepared to live outside of the closed society in which they were raised. Most have no high school diploma, or indeed any understanding of how society functions, and cannot qualify for even minimum wages jobs, causing some to have to take jobs as sex industry workers, or turn to crime. In recent years, as this problem has come to light, organizations have been formed to try to help these children.
Notable anti-FLDS activists
One of the most notable anti-FLDS activists is Flora Jessop, a former member of the Utah FLDS, who left the group and authored the book Church of Lies. Flora has established an organization and website called "Help the Child Brides" to try to assist women who wanted to leave, including her own 14-year old sister Ruby, who was forced to marry and remain in the FLDS. Flora has appeared many times in the media, and recently won her battle to rescue her sister Ruby.
Another outspoken activist is Carolyn Jessop, author of the books Escape and Triumph, her story of fleeing the FLDS, and her life while adjusting to the outside world. Carolyn was married at age 18 as the 4th plural wife to a 50-year old man. Her husband Merril Jessop was one of the more powerful leaders of the group.
“”The night my father told me that I would be married, he made me sleep in my mother's room. I never was allowed out of their sight the entire time until the marriage took place a few days later.
Carolyn has testified at trials against polygamist FLDS members, including leader Warren Jeffs.
In the media
“” BREAKING THE FAITH shares the story of eight young men and women who are trying to build a new life outside of the FLDS – either by choice, or by force. The young men, known as lost boys, are cast-outs from their homes and not welcomed back, while the women are escaping the controlling ways of the community – including arranged marriage and a life of complete submission.
and Escaping the Prophet:
“” ESCAPING THE PROPHET is a new series that follows ex-FLDS member Flora Jessop on her mission to take down one of the most dangerous polygamist cults in America. Flora, a social activist, an advocate for abused children, and the author of the 2009 book Church of Lies, had endured extreme abuse during her life in the church, until she escaped at the age of 16. Now, she works closely with law enforcement, the Attorney General of Arizona, and a network of inside informants to help rescue runaways and extract victims within the community…
- https://www.au.org/church-state/january-2014-church-state/featured/american-theocracy American Theocracy? In The Short Creek Community Of Southern Utah, A Self-Proclaimed Prophet's Laws, Critics Say, Supplant The US Constitution
- Krakauer, Jon. Under the Banner of Heaven: A Story of Violent Faith. New York: Doubleday, 2003. Print.
- Jesse Hyde and David Voreacos, The Polygamist Accused of Scamming the U.S. Out of $500 Million. Bloomberg, 24 June 2019.