[Help Needed] How to prevent anonymous access to resources(poster) on Jellyfin server

[TheDreadPirate]

Someone would need the exact path for the image or intro. I'm sure you've noticed that the links for most things in Jellyfin contain really long strings of random characters. So someone would need to brute force your server to find even one publicly accessible item. Nobody is going to spend the time to do that for a random person on the Internet's Jellyfin server.

At a minimum go to Dashboard > Users, and in each user check "Hide this user from login screens". If you don't hide users the login screen it will display all the users available, removing one barrier for a hypothetical attacker.