Just looking at this post as an example, on lemmy.world show it has 29 comments, but when i open it, there are now only 3 or 4. I replied to one comment, the user i replied to got banned, and the whole comment tree is gone from lemmy.world. Other instances still show all comments, including those from the banned user and my reply. I think it’s very confusing when a single post appears with different comments on different instances, and have no idea how this works.
Edit: why am i forced to upload a photo for a new post?
Well, the different "instances" are different websites, each hosting and serving their own copy of the original post and comments. You're interacting with your local copy, and your comments are forwarded along to the original website. The original website then sends out copies of your comment to all the other websites that have requested updates.
If your website has banned someone, it will reject content from that user. That's what being banned means: I refuse to host your posts. Just because your posts are being routed through a 3rd party doesn't mean I want to host them.
Like, if you got banned from Reddit, they wouldn't let you post there, either. If you commented on a mirror of a post, hosted on a different website, you wouldn't expect that comment to show up on Resdit, would you? Well, that's what the fediverse is: a network of content mirrors. Yes, they're mirrors that, generally, tey to synchronize with each other, but they're still mirrors. And independent mirrors at that.
They will never be perfectly synchronized. There's no true Lemmy to reflect. No whole. There is only what is locally hosted.
Thanks for the explanations. So a single post can have different comments showing up on different instances. So when selecting an instance, not only do we need to consider what other instances they defederated from, we also need to consider their policies on banning users and removing comments. Great. And people wonder why the average person isn’t embracing the fediverse.
You know you can host your own instance, with your rules, and every like-minded individual can join you (either locally or exchanging federated content with your instance).
That is what I did, btw, not because of “moderation” related issues, but because I don’t want to freeload on someone’s resources.
To be honest I don’t get what your problem is. This is not criticism; I just have no idea.
Yes, i know i can host my own instance. But I don’t think that should be necessary. My ‘problem’ is that a single post is looking different on each of the instances I signed up to, and the community in question is not on any of those instances. That is confusing me. I get that any instance can block other instances, or specific communities on other instances, and that’s a good thing. But selective federation at the level of posts or comments is an extra complication in the user experience i wasn’t aware of. I thought a post, with all its comments, would either show up in its entirety or not at all. That is clearly not the case.