Piston Duping Glitch Still in game...

This is a piston duplication glitch it can dupe any item in the game and ruin a server really quickly. it works by putting an item in a chest and putting a delay on a redstone timer for it to shift the chest over but before it shifts over you quickly grab the item. here is a video on the exploit if you do not understand what i mean. https://www.youtube.com/watch?v=WflwSSkLU1c