What should I know about Bill Mahr?

I just watched a segment on The Daily Show with Bill Mahr talking about his new film, Religulous. I have fallen in love with him based on this guest spot! (Ok, I’m being facetious, but he has managed to verbalize my own feelings about religion more effectively than anyone I have ever encountered.) Otherwise, I know almost nothing about him. Are there any scary skeletons in his repertoire that would be likely to change my impression of him?