Scott Sumner does a good job of describing the Fed:
In the past, "unusually severe and persistent recessions" tend to occur when the economy is at the zero bound. Even worse, these recessions are almost certainly caused by a failure of monetary policy. The Fed persists in viewing itself in a role similar to a fireman, rescuing the economy when it goes off course. But that's not at all the right metaphor. They are more like a ship captain, steering NGDP or inflation, and if the ship is off course it's because they've done a poor job in steering it.
[emphasis added]
He also continues to emphasize that low interest rates are NOT necessarily a sign of monetary easing. I really like reading his blog posts.