I'd like to be able to restrict the amount of item farming that can be produced via building 'mob farms' and the like but I know of no method to do this. One 'simple' idea would be to impose global limits on how many items can spawn/be picked up. For example I might set a global limit of 20 gunpowder an hour and after that amount is picked up by the players no more gun powder will drop until next hour. This same method could be imposed on sets of chunks so players on one side of the map don't stop totally unrelated players to not be able to collect loot.
