Back in 2010 or so, I used to hang out at /r/anarchism on Reddit. It was a neat place to talk about how different strains of anarchism attempted to solve the problems of crime and invasions and economics without a state and money.
There were a few anarcha-feminists around, which worked all right for a while. But then they found a dangerously misogynistic troll who made them uncomfortable, and they got them banned. I think the story was that they were an outsider and troll sent over by the Mens Rights people to spread hate and misogyny or something. Nobody was willing to go out of their way to argue against banning such a person. But then they found a few more. The precedent had been set, and only a few people spoke up against the further banning, and those who did thereby outed themselves as misogyny apologists as well. Then, partially because there were so many "trolls" to ban, and partially because of the weak controls on who got to be moderator, some anarcha-feminists got moderator positions, and started banning and deleting the comments of the "trolls" who were making /r/anarchism an "unsafe and unwelcoming" space for women.
At this point, a more broad backlash started up. People were upset about the seeming violations of free speech, and how much non-spam stuff the moderators were removing. At some point, the moderators decided that the whole discussion was unproductive, and made a policy of deleting complaints about the moderation policy. They also were by this time consistently deleting everything that might make non-whites and non-men feel "unsafe", and banning repeat offenders. Some of the other moderators were against what was happening and started to interfere, so if I remember correctly the anarcha-feminist moderators somehow removed all the other moderators who weren't on board with their program.
Eventually the (anarcha-feminist) moderators replaced the black flag banner with the black and pink, and declared officially that there could be "no anarchism without feminism", and anyone who disagreed was dangerously misogynistic and had to go. I didn't really care one way or the other about feminism, but as something of an outsider, the whole incident seemed totally stupid. I wanted to talk about anarchism, not feminism, but somehow these people had taken over and ruined everything. I got bored and left for greener pastures.
Instead of laughing at anarchists for the irony of creating a totalitarian system for themselves, we should be alarmed and take note; a community of people absolutely opposed to oppression and authority and violations of individual rights wound up oppressing each other with arbitrary authority leading to the destruction of the usefulness of their community. We can scoff and write this off as an isolated incident or an inherent failure of anarchism, but we've seen similar happening or trying to happen all over: Effective Altruism, the Tech Industry, Occupy Wall Street, the Video Game Industry, and many other places. A pattern emerges in these examples and demands some investigation.
The pattern is that "Social Justice" affiliated ideas come to increasingly dominate discourse and then administrative power in a community at an accelerating rate until some drastic outcome ends the process. This usually involves witch hunts and moral hysteria against the community members least in line with some ideological standard (typically presented as "basic human decency"); rhetorical interference, strawmanning, and denial of the existence of legitimate concerns against people uncomfortable with the events; help from naive administrators who try to appease the ideological interlopers or even thank them for their courageous efforts; and people gaining status in the community for ideological policing rather than direct productive achievements towards the shared community purpose. The end stage, if not total collapse with everyone leaving, is typically the community's resources being redirected to some purpose other than its original intended purpose, often the promotion of "social justice" ideas and causes. A sort of "ideological hijacking" of the community.
The ideological hijacking of a community in this way will almost always be harmful to the original purpose of the community. So regardless of one's opinions of the correctness of whatever ideas are involved, if a community is has some real purpose, it has an interest in effective ideological security.
The first steps, I think, in protecting our communities against ideological hijacking is recognizing the existence and pathology of the phenomenon, and understanding how it happens, so that we can design counterstrategies to be implemented by community members and administrators. This is a huge topic, but we can start with a few hypotheses to explain how ideological hijackings happen, and why they so often have the Social Justice features that they do:
Ideological hijackings like these are a spontaneous failure mode or result of a widespread vulnerability of human communities, with the social justice leftism stuff just standing in as a common available ideology to take advantage of it.
These ideological hijackings are the result of a conscious conspiracy of social justice wizards plotting in the back room to take over the world one internet community at a time.
"Hijackings" like this are just the removal of unprincipled exceptions to a widely held moral code that, when consistently interpreted and applied, demands that all communities must be primarily concerned with social justice issues.
"Social Justice" is a sort of semi-autonomous collection of ideas evolved or designed like a rudimentary fungus to take root, grow, take over, and expand from communities in certain conditions.
In complex phenomena like this, hypotheses typically aren't mutually exclusive. Each one of these factors is probably insufficient or implausible to explain the phenomenon on its own, but my bet is that each one of them is playing an important role. In any case, a wise program of ideological security will explore and address each one so that no vulnerability exists.
While more extreme responses exist, and we can get very deep into the analysis and theory, there are a few things we can keep in mind that will probably help secure our communities against ideological hijacking without having to install a grand inquisitor:
Ideological security is an important matter for purposeful communities. You can't avoid politics in primate social groups by pretending it doesn't exist. Every public action has political consequences, and every explicit or implicit policy of action has potential vulnerabilities to ideological exploitation.
Seemingly overreactive complaints about, for example, creeping social justice totalitarianism in response to seemingly innocent vocalization of feelings of unwelcome or something, are not baseless, and have real precedent behind them. Social Justice Ideological Hijackings are a real phenomenon.
Do-ocracy or "Shut up and show us the code" or local equivalent is a good immune defence against outsiders and non-contributors manipulating the community without actually doing any good work for the community. If status is tied to advancing the group's shared interest through humble work, then the community will flourish and be secure against many possible attacks.
Everybody having "no friends to the right and no enemies to the left", that is, everybody being willing to denounce those more "abhorrent" than them as "too far" in the hopes that it will shield themselves from such denouncement, leads to a debilitating moral signalling spiral that can result in ideological hijacking. The antidote is to refuse to simply denounce people for having unacceptable opinions, and instead argue rationally with them.
A few people taking a stand and growing a spine instead of capitulating to a "majority" that considers their opinions unacceptable do a great public service in that they hold the range of thinkable and expressible positions open as per Asch's Conformity Experiments. Contrarians act as a canary in the totalitarian coal mine, and a dead canary signals people to stop thinking and keep their opinions to themselves.