Container Key

The Container Key might prove a pretty useful utility to those keen on protecting their belongings. By Shift-Right-Clicking on any container (eg. Chest, Furnace, ...) it will be locked and can only be opened again using this one specific key until one chooses to unlock it again. This can be done just as easily by Shift-Right-Clicking with the key again.

One should keep in mind however, that, to those so inclined, overcoming this protection should prove trivial by simply destroying the container in question.