Something's brewing between Cardinal Capital Management and infoUSA. The latter, an Omaha, Neb.-based sales and marketing giant, has sent a letter to the Securities and Exchange Commission to "look into the trading practices" of the former, a Greenwich, Conn.-based hedge fund. The company claims that since October, Cardinal "has been in possession of non-public confidential information provided by the company pursuant to a confidentiality agreement," and, according to infoUSA, Cardinal has filed a Form 13D/A "disclosing that it had purchased infoUSA stock while in possession of this information." The SEC move follows a complaint filed by Cardinal in Delaware Chancery Court, which was filed under seal as a derivative and class action complaint in accordance with confidentiality agreement in which Cardinal demands an "inspection of corporate records." Meanwhile, infoUSA mentions, in its release about the SEC letter, that the HF complaint relates to events in 2005 and earlier "that have been publicly used by Cardinal and others to further their own short-term interests." The Nebraska firm says its views the Delaware allegations to be "without merit."