Are you new to online communities? I've been a core member of several for years.
There's always politics, admin only channels, and people contacting each other outside the main system. Sometimes multiple levels, like two admins talking in private, then adding a third, then bringing it into the admin channel, then breaking the news into the main community.
In communities where there's external attacks, or a concern with reputation, the people in charge typically take that seriously. It's very possible that something is publicly forbidden, but with the right contacts you can find the right people.
> Create an alt account on KF and post in a lolcow's thread saying that you want to harm that person in real life.
Which is unsurprising because formerly kiwifarms used traditional hosting, and had to at least keep some plausible deniability. But everyone knows what all that stuff they post is for.
> You'll be downvoted into oblivion, probably banned, possibly doxed if you used the same username as you use elsewhere, and possibly reported to law enforcement.
Sure, and if you know the right people on the right Discord, then you can avoid all that and discuss all the plans and share all the juicy news away from prying eyes.
Besides which, the info is public. Anyone can act on it without being a member, or having any agreement on anything with people posting there.