The server im in has a player who's just been messing with my paintings by adding obscene images and filling my place with them and there's nothing the moderator can do short of straight up banning them from the server, which they wont because the moderator views this constant harrasment "harmless fun." A blacklist for players so that they wont have access to paintings or destroy them but stilla ble to view them would be very helpful and I dont have to have to knock off every single painting griefing my house.
(1.18.2 server)

there's nothing the moderator can do short of straight up banning them from the server

Well, thats the expected response to a server ToS violation, I'm not sure if this should be handled on a per mod basis. 1.21+ also has a NSFW feature to handle this case.