Technically, if you post a picture from lemmy.ca to a different instance, the picture is stored on lemmy.ca's server, so yes, that would be against the rules, as that is what i'm trying to avoid.

I would say a general rule of thumb (as a lot of instances have similar rules, but they're probably enforced differently) that you try and follow the rules of both the instance you're posting from and the one your posting to. the community itself can have it's own set of rules too.

As to where the content itself is stored, technically, they're stored in both places. if you delete your account, i believe it gives you can option to delete all your content as well, and those deletes will be federated as well.

That being said, if one instance goes down, or an owner takes it down, or whatever, any content that has already been federated to other instances are already there, ie, stuff should still work, for the most part, with probably the exception being any images stored locally on the instance that is down, since images themselves don't federate across instances.

Also, a quick disclaimer, all of the above is all stuff that "i'm pretty sure on", haha, just from my understanding of how things work around here. If i'm wrong on anything, feel free to correct me!

To try to give you clarity. The "true copy/original version" of every comment you make is stored on your server. When you click the Fediverse icon (the rainbow star thing) link to your comment it will be of your server, and other server user's content will be on their own domain when you click on the icon within their comment.

Copies of this comment are stored on every server that accesses that post thread that federates with your server. Any changes made will propagate when the copies sync up to the original, including deleted status. If the original server goes down unexpectedly or defederates, the copies on other server no longer sync and remain as they are.

Technical aspects aside, when you post in a community on another instance, you need to follow the rules of that instance. However as a user of your home instance there might be certain expectations placed on your conduct. (Here it seems like don't upload large files is the main thing.)

If I were running a server, and I saw one of my users behaving poorly elsewhere, I would absolutely consider their behaviour fair game for a ban. It would depend on the behaviour. Someone posting on a porn forum somewhere, meh. Someone posting about how [ethnicity] should all die in a fire, welllll, yeah, I don't want that person. Find somewhere else to be.

No. You need to follow the rules of the instance you are posting in, not the instance you are viewing the content from

Where did you find those awful images? Asking for a friend who would definitely want to avoid them.

I think they should.

Hopefully your home instance has rules that facilitate having a safe space online regardless of where you are posting to.

Otherwise if you are doing something like promoting "othering" or denying the Holocaust or the moon landing, etc, you may end up getting your instance banned from federating with servers where the mods don't like what you're posting.

If an admin has power over your account or your content, the rules they state apply.