I received an email from Plex notifying me of a data breach and requiring me to reset my Plex password.
(I use a dummy email address with unique password [now changed] for my Plex account and use server and clients in LAN-only mode so am not worried about this… YMMV)
Ars Technica article: Plex imposes password reset after hackers steal data for >15 million users
BleepingComputer: Plex warns users to reset passwords after a data breach
The Register: Attacker snags account details from streaming service Plex
Interestingly the Plex website shows no information about this in its News blog (no news since May 2022) but shows that Plex has more than 25 million users.
Hope this helps…