From the story:
These five companies waged an 18-month Freedom of Information battle with the Mercury News, convincing federal regulators who collect the data that its release would cause "commercial harm" by potentially revealing the companies' business strategy to competitors.
Meanwhile, companies like Intel, Cisco Systems, eBay, AMD, Sanmina and Sun Microsystems have apparently freely supplied their race and gender data to the Mercury News.
Why all the secrecy? I'm not sure I see the connection between race and gender information and a company's evolving business strategy. So race and gender are now trade secrets? Interesting.