In the same article, he reports that Doug Bandow accepted payments of as much as $2,000 a story for pieces favorable to lobbyist Jack Abramoff's clients. He has resigned from the Cato Institute in the wake of the story, exposed by Business Week, issuing a statement that "I am fully responsible and I won't play victim ... Obviously, I regret stupidly calling to question my record of activism and writing that extends over 20 years. . . . For that I deeply apologize."
Peter Ferrara of the Institute for Policy Innovation is unapologetic about accepting similar payments; Jonathan Adler of the National Review reports that he was offered similar payments when he worked at a think tank but declined them. It's more evidence that think tank output tends to be generated by starting with paid-for conclusions and generating arguments and selecting evidence to support them--similar to Feith's selection of intelligence information to support the invasion of Iraq. Think tanks supported by particular interests simply aren't a good way of getting objective information.
More examples in Kurtz's piece.