My users have been desperately trying to inflate our economy to death by making monster grinders through a variety of ingenious methods. It occurs to me that some sort of time delay might do wonders for making this untenable. For example, after three/four kills in rapid succession, the user is penalized and cannot gain rewards from killing monsters for the next 30 seconds, or something similar.

Cheers,
-Dirk

Hmm, interesting concept. Marking this as a feature request.

I was coming on to suggest something like this. I'm having the same problem, monster grinders are still very effective if the player sits there and swings their sword for an hour or two on end.

Disabling money and mob drops by rate-limiting them to say, 5-10 per 60 seconds would fix this problem.

Addendum: Splash poisons would also have to be covered.

There is a undocumented feature in the dev build to mark mobs from spawners to give no rewards:

    Hunting:
        # Determine camping by remembering entities spawned by mobspawners.
        # Default: false
        CampingByEntity: false

Try it out and see if that solves this problem.

I use that already, but it penalizes blaze spawners pretty hard.