Moderator Molly Wood, executive editor at CNet.com, said Facebook didn't feel it had any staff at SXSW who could speak on the issue. Google's privacy counsel Will DeVries was scheduled to participate but bowed out, citing ongoing litigation with the privacy advocacy group Electronic Privacy Information Center, whose representative Lillie Coney was also on the panel.

Coney said that EPIC was not in litigation with Google, nor does it ever sue corporations. EPIC did recently the U.S. Federal Trade Commission, pushing it to take action to block implementation of the company's controversial consolidated privacy policy that took effect March 1. EPIC lost that suit, although it could appeal to the Supreme Court.

Coney called Google's apparent understanding of the action as legal action against the company as "a very strange way to take the regulatory process and the mechanisms that are available to civil society, or even individuals".

Google did not respond to requests for comment.

Even without Google and Facebook in attendance, the panel was hard-fought as Coney and Jay Stanley, a senior policy analyst with the American Civil Liberties Union, battled Berin Szoka, president of the libertarian-leaning nonprofit TechFreedom, over whether the collection and increasingly sophisticated analysis of large amounts of user data for use in corporate marketing constitutes a real harm to consumers and whether government regulators should step in.