In a rare interview, David Koch, the billionaire known for bankrolling conservative causes, claimed he didn't know Scott Walker's name before someone impersonating Koch prank-called the Wisconsin governor. “It's a case of identity theft,” Koch said, adding that now whenever he calls a lawmaker they'll think he's a phony. Koch said that he feels he's been vilified for supporting conservative causes, which includes opposition to the health-care bill, questioning climate change, and contributing campaign funds to Walker and other conservative candidates. Koch cites the millions he's given to fight cancer, and the multiple research centers he's opened. “I read stuff about me and I say, ‘God, I’m a terrible guy,’” he said at the opening of the MIT David Koch Institute for Integrative Cancer Research, which he put $100 million toward. “And then I come here and everybody treats me like I’m a wonderful fellow, and I say, ‘Well, maybe I’m not so bad after all.’” But at times his goals run at cross-purposes: One of his companies, Georgia-Pacific, has been trying to convince the government not to list formaldehyde as a human carcinogen.