This has nothing to do with monetary policy, but Ben Bernanke's explaination to the FOMC board of why Greg Ip is a great reporter is pretty solid:
CHAIRMAN BERNANKE. I have the less pleasant duty of reminding everybody about the Wall Street Journal article on our communications policy that appeared some time ago. I don’t think anybody actually leaked the story, because the way Greg Ip works is that he goes around and talks to each person and gets a little of the story and then builds it up in that way. Nevertheless, I think it is obviously bad for our institution when our internal deliberations become public, and so let me just ask everyone, please, to be especially careful about maintaining confidentiality. Thank you.
That is, in fact, how it's done.