This isn't anything new, people don't seem to make the connection very often, but this kind of behavior is ancient and just takes different forms from time to time.
The disease is the moral authority police & moral superiority complex.
Humans have this compulsion to be "right", to punish people for not being righteous enough, and generally to cultivate a feeling of their own moral superiority.
This is accomplished with rules, usually somewhat vague and needing the ability to be misinterpreted, overinterpred, or just somewhat related to "punishments". If your policy is "don't be a jerk" it's quite hard to misinterpret that into zealotry, but a complex code of conduct? That's the meat and potatoes of this human failing.
People rejected organized religions because they were full of this kind of person, pepperpots determined on punishing each other and everyone else. The failing logic is that this sort of behavior was caused by organized religion.
The self-righteous and overzealous young people (and not so young too) just changed topics, they aren't thumping their bibles of soap boxes about not loving Jesus the right way or following god's will (some still are, just fewer) the pepperpots of today are getting up on their social media soapboxes and doing their morality masturbation about their brand of justice.
The insidious thing, or why they are so widespread and successful is that their message and their sets of rules, on a quick glance, seems reasonable and rather supportable by most folks. The people disagreeing with this new justice are usually the ones yelling nonsense and that opposition draws battle lines where a lot of people pull themselves into the "justice" side to disassociate themselves from the vocal opposition because they can't quite figure out what is wrong with the justice crusaders.
It is very difficult to pinpoint exactly what is wrong with this new generation of moralists, so most people stay pretty silent about it.
It's not new, just the same old monster in a different costume.