Players can use a hack known as 'Freecamming' or use lag to break a wall and quickly access a Chest/Crafting Table/Furnace without actually being able to see it. It's quite common on my server and very annoying. An example of these griefers & hackers: here.
This plugin stops players from interacting with blocks they aren't looking at. It allows additional blocks to be added to the config if necessary, and you can add any blocks I've missed that are partially transparent (Or whatever you wish to call it).
See it in action here: http://youtu.be/2Ci-FKQzJGs
Players with the permission node chestfix.notify will be notified whenever a player attempts to use an object they can't see.
Players with the permission node chestfix.bypass will be able to bypass this plugins protection.
It automatically protects:
And is configurable to protect more!
Checkout the config over here http://dev.bukkit.org/server-mods/chestfix/pages/config/
