Quarter inside Macbook Pro i7

Upgraded my Macbook Pro from 4gb to 8gb. When I opened the back, I found a single quarter on top of the multi drive. My Macbook Pro is running great with 8gb, but I really want to know why there is a quarter in my machine that I ordered directly from the factory and shipped from China. I called Applecare, who had ideas, but wasn't really sure himself. Below is the video of my discovery on YouTube.

http://www.youtube.com/watch?v=xb0fHSKWqv8