Some people think the Federal Reserve keeps all of the interest the government pays to it. This was true up until the early 1940s. It has not been true ever since. The law was changed during WW II.
Every year, the FED repays most of the money to the government. For 2012, it was $88.9 billion.
This payment will not register with most FED-haters. They think the FED is there to make money for itself. This is hardly the case. It is there to protect the largest banks. It is there to provide fiat money for the government. It is there to prevent market forces from bankrupting large banks.
Sadly, the people who hate the FED rarely understand how it works or why. They think of the FED as a scam to make money out of nothing. It is in fact a scam to keep large commercial fractional reserve banks profitable from loans and investments they make, which then go sour and threaten these banks with bankruptcy. It is a scam to protect scammers. It is indirect, not direct. It is not based on profits it takes from counterfeit money it creates. It is based on profits for commercial banks on counterfeit money they create: fractional reserves.