As a Nightmare Fuel page, all spoilers are left unmarked.
The Book:
The basic concept of the Insight. Having an implant that can display all sorts of information, music, tv shows directly onto your iris as well as be used for communication with your friends and family may sound practical in theory, but when this implant also constantly monitors each and everything you do, always ready to punish you if you commit an infraction, it starts getting horrifying.
It´s mentioned there was a way to get around the Insight noticing something: Doing it while blindfolded, this included parents being forced to interact with their illegal children only while blindfolded.
Also, you were not only watched constantly by your own Insight but everyone else as well, meaning that even if you could get around your own your secrets could still be discovered at any moment. Such as when Sonya caught just a peek of Grace Ward through her home window.
Sonya even thinks fondly of her Insight, having considered it a friend, and sometimes even revealed her private thoughts to it. Just shows how deeply the indoctrination of the Delegation went.
After the rebellion the Triumvirate deactivated everyone’s Insight, except of the people within the Aperture. For them they only disabled the practical functions. Sonya even muses if they are still watching their captives through the Insight on occasion, meaning even locked in a ghetto they can never feel truly safe from the rebels.
Living under the Delegation in general. Apart from religious activity, pretty much everything you did was either rewarded or punished via the Des Coin system. Meaning even small things like not sitting straight would cost you money. It`s a society that always requires you to be your best self, to behave and make no mistakes, or otherwise you might have your entire life destroyed.
One line by Alexander about Sonya`s short haircut implies that women wearing their hair short was considered an infraction under the Delegation. If you are a woman who likes to wear her hair short imagine having to pay money for that 'privilege' every day. A thought by Sonya in the same conversation also implies that the same was true for men keeping their beard not perfectly neat.
It´s suggested that the Delegation would regularly 'disappear' people with a low Des Coin count. Meaning that, especially for the poorer parts of society, one single misstep can mean your end. And not just yours as the Delegation will likely kill your family as well just to be sure.
Later Sonya finds out that people would be punished differently for infractions depending on what position the Delegation had in mind for them. For example, her swearing in public cost her more Des Coin than it would have her sister, as Sonya was destined to become a Trophy Wife while Susanna was set to take a position within the regime’s leadership. Implying the higher your position in society the lesser the punishment's.
The thing that would earn a person the most Des Coin was to report the illegal activities of others to the government. Sonya in part snitched on Grace Ward so she could 'pay' for her first time with her fiancée Aaron. If one follows that train of thought, it is very likely that various people all across society constantly snitched on their neighbors and family members to keep their own Des Coin counts high.
As a bit of Realism-Induced Horror the "Social Credit" system that the Peoples Republic of China practices is horrifyingly similar to the Des Coin System in the novel. Given that China also used to have a strict One-Child-Policy it is likely the parallels are deliberate.
Speaking of Delegations harsh One-Child-Policy, they justified it with the alleged limited resources in the post collapse USA but would regularly allow their leading families special exceptions within it, such as Sonya`s and Alexander`s family. If illegal children were discovered with poorer families though they were given up for adoption.
As Sonya later finds out, the illegal children already old enough to remember their birth parents were instead killed by her father on orders of the Delegation, just on the off chance that they might feel resentment on having been torn from their parents. This includes Grace Ward.
While the Triumvirate has returned many of the children to their original parents this hasn't come without troubles either, as many of these children had long since gotten close to their adopted parents and were now torn away from them to live with their birth parents they never knew.
The Rebellion, while the above examples should make it clear that the Delegation was a horrible regime that needed to go, what we hear of the revolt that eventually overthrew it is horrifying as well. Pretty much every person in the Aperture has lost most of their family during the fighting.
It´s mentioned several times that the rebels would indiscriminately kill people connected to the Delegation, including their children. Some examples include Sonya`s fiancée Aaron who was killed during the riots and her best friend Tana who was killed alongside her entire family when they tried to flee the city. He Who Fights Monsters indeed...
We also hear several times of people selling out their own family members to save themselves. In several cases, such as Alexander`s it was children selling out their parents, but also hear of one chase were a mother sold out her daughter to the rebellion to save her own neck.
Other families were collectively Driven to Suicide such as Sonya`s in an attempt to escape an even worse fate at the hands of the rebels. Also, as in the case with Sonya`s family this often included the parents trying to drag their children with them to their graves. (Which of course is a thing seen in the final days of RL dictatorships as well, such as many Nazi leaders killing themselves alongside their families)
The Aperture, while many people locked in here were guilty of being part of the regime, the story makes isn't shy in talking about the terrible conditions within the ghetto.
The Rebels threw everyone into the Aperture they connected with the Delegation (save those who sold out others to the rebels) which includes their children and family members who were forced to live there just for being their parents’ children. And had Rose Parker not eventually written her articles about the children of the Delegation they would have remained there for the rest of their lives.
There is only one room in the Aperture that can be locked: The makeshift doctor’s office. Everyone else can't even be safe in their own homes. Sonya actually was one evening attacked by a rapist in her apartment.
Many people within the ghetto have turned to hedonism, drinking large amounts of self-brewed moonshine, and overdosing on drugs, driving many of them into an early grave.
People from the outside world actually enjoy climbing on buildings surrounding the Aperture to watch the captives in their misery. Sonya, having an apartment facing outward has hung sheets in all her windows to get at least some privacy.
During their visit to the Aperture the Triumvirate leaders specifically tease Sonya about her lot in life. Showing that the people in charge of the new society, while certainly not as bad as the Delegation, are not above petty Kick the Dog when they feel like it.
During one of the prior visits some drunks threw a few bottles at the Triumvirs. Their reaction was to cut the food supply to the ghetto for weeks, leading to the inmates starving.
It is implied that good looking female inmates are driven to engage in Sex for Services with some of the guards of the ghetto.
The Analogue Army, a group of Evil Luddite who seek to return humanity to an age before modern technology. Committing murders and bombings shows that the world the Triumvirate built still isn't all that peaceful or secure.
The fact that Easton Turner, a major collaborator of the Delegation with ties to the Analogue Army was able to weasel himself into becoming one of the three leaders of the Triumvirate. While he is exposed at the end who knows if he was the only one like him who managed to get into the new government.
