ENTERTAINMENT
08/14/2009 05:12 am ET | Updated May 25, 2011

Jonah Hill's Twitter Nightmare (VIDEO)

Jonah Hill was on Letterman Monday night - and if you're one of the thousands following what you think is Hill on Twitter, you've been duped.

"I have never been on the website Twitter nor will I ever be on the website Twitter," Jonah told Dave.

The account is a fake, and the impostor has even started a feud with the director of "Iron Man."

"Apparently this kid has been talking trash to Jon Favreau," Hill said, adding that he had wanted to work with the director someday. Hill even placed a real-life call to Favreau to apologize for the fake Hill's words.

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