On our server, we were using a mod to keep monsters from spawning in built areas. Now, that mod doesn't work anymore (and it's been abandoned), so this one castle is full of monsters. Last night, one of the people who lives in the castle was being attacked all over the place. He thought he was safe, and then he heard zombies beating on a door.
Wish I could have been there, sounds like a riot. Poor guy got killed several times, trying to place torches to prevent monster spawns.