Remember that one line of Justin Timberlake's from The Social Network? "A million dollars isn't cool, you know what's cool? ... A billion dollars." Well, over $1 billion worth of U.S. dollar coins seems to be cramping the style of the federal government. A stockpile of over a billion of the coins has accumulated in the federal vaults since the 2007 start of a program to put the images of every deceased U.S. president on the coins, in addition to the Sacagawea dollar coins that the government still mints.

The coins didn't exactly accumulate overnight, and observers have been concerned about the growth of unused and largely unwanted coins for some time. Just this week, three U.S. senators sent a letter to the Federal Reserve inquiring about the coin reserve, according to NPR, which has been closely following the story. And just today, California Rep. Jackie Speier called for an end to the dollar coin program in the letter to her colleagues. An earlier report from NPR puts the cost of producing the surplus coinage at $300 million.