

Option 1: Move to an instance that doesn’t federate with them, like lemmy.cafe.
Option 2: Go to the settings page on the website, and block the instance. This will stop you from seeing comms on that instance, but you will still see comments and posts by their users in other comms.
Option 3: Client-specific. If you’re using another client besides the default website, most of them have some way to block and hide all users from an instance as well, usually somewhere in the settings.
At that point, the swamp is more like flat ground