Anyone who has remote users knows that there are always a select few who share their Plex account login with others. There is a global setting to limit simultaneous streams for ALL remote users. Allowing restriction of this per user would discourage sharing without removing the user altogether.
Another useful tool would be the ability to disable specific IP addresses per user, or the ability to authorize specific IP addresses per user.
Here’s an example: I use Tautulli to monitor my server activity. I can see certain users who have clearly shared their accounts by observing IP address locations (precluding any use on cellular devices, as IP addresses vary). The only tools available to reign this in are either banishment, or limiting remote streams for everyone to 1 or 2 streams simultaneously, punishing everyone.
