I have a Synology NAS, and the account you create with them is separate from the ones you create on the device. They couldn’t log into my device. Their account allows for easy integration with their stuff like the dynamic dns or other outside services. I like it because if my internet goes down, I get an email saying they lost connection, which is great for diagnostics.

If I set up my router to block all traffic to them, it would not prevent me from using the device.

This is true. You create a plex account, which allows you to log in from anywhere and will give you access to your media. The real problem is that if your outside internet goes down, you can’t log into your own server.

My first thought was “this is why you use Jellyfin”.

I don’t see ads, so who knows what is in my profile.

That is why good sushi fish is flash frozen and then thawed before serving. It will kill all the parasites in the meat.

Reading this makes me want to find a Linux distribution that does not use the gnu stuff at all.