Updated at 10:33 a.m. PDT with comments from privacy groups during a press call. Updated again at 12:08 p.m. PDT with Google's response and comment from an Internet lawyer.
The signatories include the Electronic Privacy Information Center, Electronic Frontier Foundation, the American Civil Liberties Union of Northern California, Privacy Rights Clearinghouse, Center for Digital Democracy, and World Privacy Forum.
What's not precisely clear is whether Google is actually doing anything unlawful. Google, for its part, disagrees with such assertions.
When asked for its response to Tuesday's letter, Google provided News.com with the following statement:
The issue started bubbling up last week, when New York Times reporter Saul Hansell posted a blog entry raising questions about Google's compliance with the California Online Privacy Protection Act of 2003. By contrast, he noted, Google's major competitors--Microsoft, Yahoo, and AOL--all provide links to their privacy policies on their home pages.
But McNabb also said her office isn't tasked with interpreting the law and can't do anything more than make recommendations.
For the privacy groups who sent the letter on Tuesday, the answer is clear.
Despite criticism from privacy groups, Google has undertaken efforts designed to make its privacy practices more digestible to its users in recent months, including launching afilled with videos aimed at explaining what sort of user data its products use and store.
In a conference call with reporters Tuesday, representatives from the privacy groups said they had not attempted to reach a resolution privately with Google before publicizing their letter, which they acknowledged was prompted by the New York Times pieces. Electronic Privacy Information Center director Marc Rotenberg suggested such a move wouldn't have accomplished anything different than would a public letter.
"If Google decides it doesn't have to comply with the California law," Rotenberg said in response to a question from CNET News.com. "It does raise some very troubling questions, and we'd have to decide what to do next."
Eric Goldman, director of the High Tech Law Institute at Santa Clara University School of Law, said it's not clear whether Google is in violation of the California law referenced by the privacy advocates. "I think bright minds would disagree about whether Google is in compliance with its current implementation," he said.