Duplication Exploit

So you can put a timer on a piston via Redstone repeaters and have it rigged to move a chest. You can put a stack of diamonds in that chest, activate the timer, and pull out that stack as soon as the chest is moved. You'll be left with the stack you have pulled out, as well as the stack that is still in the chest. I find that this duplication method will potentially be unfair on for some PVP realms out there.