What legislative power has the bureaucracy assumed?

The Federal Reserve has the power to establish monetary policy, like inflation, deflation, and interest rates. This power is not given to any entity by the Constitution except Congress, making the Fed's activities unconstitutional.

Similar things can be said of almost any agency you can think of: the IRS, SEC, FTC...They all have the ability to make rules and at times the ability to enforce them. The problem is that the Constitution vests legislative power in Congress only and executive power in the President's office only.

Currently, and for the past 100 years, we have unelected bureaucratic government officials usurping the power (or, Congress and the President have let their power be usurped, depending on your perspective) that is not given them by the Constitution. How will the people have any recourse in this matter, if the people cannot elect someone in the place of the existing bureaucracy?