In the episode 'Nosedive' of Black Mirror, people are judged by a numeric rating given to them by their interactions with other people. Poor ratings, or even interacting with other people with poor ratings, can have real-world consequences, such as not being able to get on an airplane.

China seems to have viewed this dystopian story as a how-to manual.

The "social credit system," first announced in 2014, aims to reinforce the idea that "keeping trust is glorious and breaking trust is disgraceful," according to a government document.

The program is due to be fully operational by 2020, but is being piloted for millions of people already. The scheme is mandatory.

Like private credit scores, a person's social score can move up and down depending on their behaviour. The exact methodology is a secret — but examples of infractions include bad driving, smoking in non-smoking zones, buying too many video games and posting fake news online.

People with low scores can't get their kids into good schools or get good jobs, while people with good "credit scores" have all sorts of perks.
Of course, this is all about controlling people.

A 32-year-old entrepreneur, who only gave his name as Chen, told Foreign Policy: "I feel like in the past six months, people's behaviour has gotten better and better.

"For example, when we drive, now we always stop in front of crosswalks. If you don't stop, you will lose your points.

"At first, we just worried about losing points, but now we got used to it."

This much you may have already known.
What you probably didn't know is that this didn't stay within the borders of China.

“The civil aviation industry credit management measures that the airlines are accused of violating were written to implement two key policy guidelines on establishing China’s social credit system,” she explains. “Social credit was used specifically in these cases to compel international airlines to acknowledge and adopt the CCP’s version of the truth, and so repress alternative perspectives on Taiwan.”
...It is not clear whether foreign companies have access to the information kept on their social credit record, nor if foreign citizens could find out if their nation’s companies have made concessions or changed their behaviour as a result.

Well, that's just China.
We wouldn't do something like that, amirite?

Welcome to the fallout from the Russiagate scare.

Facebook has begun to assign its users a reputation score, predicting their trustworthiness on a scale from zero to 1.

...Users’ trustworthiness score between zero and 1 isn’t meant to be an absolute indicator of a person’s credibility, Lyons said, nor is there is a single unified reputation score that users are assigned.
The reputation assessments come as Silicon Valley, faced with Russian interference, fake news and ideological actors who abuse the company’s policies, is recalibrating its approach to risk — and is finding untested, algorithmically driven ways to understand who poses a threat. Twitter, for example, now factors in the behavior of other accounts in a person’s network as a risk factor in judging whether a person’s tweets should be spread.

It's not much yet, but Americans are fully on-board with more social controls.