So basically you can:

• blacklist a world so players can't spectate other players in that world, or you can
• blacklist a zone (set with world edit) so players can't spectate other players in that zone.

Hope it makes sense and can become a possible feature.

Thanks!

BoomLikeADuck

(Also when you're spectating, unless this isn't already a feature... Add an item that you right click to stop you from spectating.)

Sounds good, thanks! We'll get this added soon!

Well maybe I said it wrong. I want the players to be able to start spectating in a blacklisted world but not be able to go back to the world after they have gone to a player outside of the world.

No that's ok, I understand. I will add it soon :)