From a column by Dick Morris:

According to the Federal Reserve Board of St. Louis, the Fed is now holding upwards of $1.7 trillion for American banks, more than twice what it had in its vaults at the start of 2008. How did the Fed get the money? Congress voted the Troubled Asset Relief Program (TARP) package of bailout funds. The Fed purchased bank assets to get liquidity onto their balance sheets. What did the banks do with the money? They gave it right back to the Fed to hold in its vaults. They didn't lend it out. They didn't use it to stimulate the economy. They are using it for a nest egg to tap when times improve. Just like the theory of rational expectations says they would.