CEO Tim Cook has been ordered to testify in the Department of Justice's antitrust case against Apple, Reuters reports. US District Judge Denise Cote has asked Cook to provide four hours of testimony, fulfilling requests by prosecutors, who have argued that the executive likely has relevant knowledge of Apple's 2010 entry into e-books with the iBookstore. Apple opposed involving Cook, claiming that the deposition of 11 other executives made the CEO's participation "cumulative and duplicative." Cote, though, has taken the position that the passing of Steve Jobs -- in charge of Apple at the ti