The data show diversity in Silicon Valley remains a serious issue. Some companies cite a "pipeline problem," saying too few minorities and women are graduating with technical degrees. Others argue that people tend to hire people like themselves, and in tech, that's largely white and Asian males.
But the biggest obstacle, according to industry experts, is that few are talking about the problem.
"This data is a just a baseline for discussion, but we can't end the problem if we can't start the conversation," said Aditi Mohapatra, associate tech sector director at BSR, a consulting group that works with companies on social and sustainability issues. "For the tech industry to remain silent about diversity is so not aligned with what they preach."
The Department of Labor said it does sometimes go back to companies and demand defense of their claims.
In "rare" situations, the DOL said, this can escalate into lawsuits between the government and the companies.
But lawsuits and appeals take time and money, and there's no guarantee of data waiting at the end of the road. Mike Swift, a reporter with the San Jose Mercury News, began probing the topic in 2008 by sending similar FOIA requests for data from the region's 15 largest employers.
His inquiry sparked a two-year legal battle, resulting in access to data from just one company -- HP -- that had opposed its release.
The Black Economic Council and the National Asian American Coalition have also attempted to uncover diversity data at major companies, but most of those requests have turned up little information.
"Companies are happy to hide behind a law that provides so little access to this data," said Sims, the law professor. "Tech is the most vibrant sector of the American economy, and rather than trying to fix problems, they want to keep secrets."