Reddit has informed moderators of communities that are still private in protest that they will lose their mod status by the end of the week. Thousands of communities went dark earlier this month to push back on the company’s planned API pricing changes.
They don’t tie into each other in the sense that they share login credentials or anything like that. But they do send messages - posts, comments, favourites, etc. - to each other, if those messages are requested, creating a network of synchronizing content mirrors.