Eight of California’s largest newspapers — including the Los Angeles Times, San Francisco Chronicle and the San Jose Mercury News — and The Associated Press are supporting three online Mac journalists who published details on an unreleased Apple product. The organizations submitted a court brief last week asking that the Mac sites be allowed to keep their sources confidential in the case brought on by Apple. “The media companies said [judge] Kleinberg’s ruling, if upheld, could impair the ability of all journalists to reveal important news, from financial corruption to government cover-ups. Before demanding that the online publishers’ Internet provider turn over e-mail records, the companies said, Apple should ‘exhaust all alternative sources’ of identifying the source of the leaks.”