It's right there in the open on Michael Moore's own website, on his "Must Read" (recommended links) page. One of the sources he cites for "Real News" -- at the top of the list, just under MediaChannel.org -- is The Onion.
Now I get it. "Michael Moore" is a hoax persona, like those generated by Alan Abel and Joey Skaggs. Heck, maybe he is Joey Skaggs: It would be perfectly in character, save that "Michael Moore" has lasted longer than Skaggs usually allows his "performance art" to run before confessing.
But then some people still believe The Blair Witch Project was a documentary, too.
(See also Hoystory and Ipse Dixit.)