Bix Weir, love him, hate him - he just identified a motherload of United States silver that was secretly "sent elsewhere" during WWII.
Very cool story and after listening to his video, below, I realized that there is a possible corollary to the silver's movement, that may have driven the price of copper up too high for use in our pennies.
Make sure to give Bix a big thumbs up: www.youtube.com/watch?v=R_kR9d8j6vc
"The Road to Roota" refers to the Root user of a computer. Specifically rootA. Makes it sound much cooler, knowing that.
IMHO Bix is worth checking out.