Reddit users have no idea, and no control, over whether their posts are mirrored.
I can’t believe that I actually had to say this, but what these bot instances are doing is EXTREMELY ILLEGAL.
Reddit comments are COPYRIGHTED materials, and when reddit users sign up, they agree to a ToS that grants reddit essentially a permanent license to do with the contributed content as reddit pleases. However, anyone else mirroring these reddit comment would not have permission to do so, and theoretically reddit, or any reddit user whose comments are being mirrored, can start issuing DMCA takedowns against any instance that host these comments by federating with these bot instances.
I’m not a lawyer, but @rgullis, instead of saying they are archivers or frontends that explicit do not host contents, you are ACTUALLY dumb enough to admit that you are illegally scraping, mirroring, and rehosting reddit’s content for the explicit purpose of making a competitor and harming their commercial interest so you can’t even claim fair use. You better pray that reddit’s lawyers don’t find out about your little projects, they’ll find you through your domain registrar or your cloud host, and you, and any instance that federates with yours would be in a world of pain.
Any instance owner should defederate from these bot instances immediately.