The Electronic Privacy Information Center asking the U.S. Court of Appeals for the Fourth Circuit to uphold privacy advocate Betty Ostergren's First Amendment right to publish the numbers.

In its brief, EPIC noted that Ostegren's advocacy work is focused on getting state and local governments around the country to stop posting unredacted public records containing Social Security numbers and other private data on their Web sites. As part of an effort to highlight the problem, Ostergren has taken the Social Security numbers of prominent people she has found in public records and republished them on her Web site.

When a person publishes lawfully obtained and truthful information, that action is "pure free speech," said John Verdi, senior counsel at the Washington-based EPIC. "It is exactly the type of speech that is protected by the First Amendment."

Ostergren runs the Web site, which she has used to highlight identity theft risks that can result from the posting of unredacted public documents, such as land and tax-lien records posted on government Web sites. Over the past seven years, she has chronicled dozens of cases where local and state governments have inadvertently exposed thousands of Social Security numbers and other personal data on their Web sites, making them attractive targets for identity thieves.

As part of the campaign, Ostergren routinely posted the Social Security numbers of high-profile individuals that she obtained from county and state government Web sites. The list includes former Florida Gov. Jeb Bush, former U.S. Secretary of State Colin Powell, former U.S. House Majority Leader Tom DeLay, former Missouri Sen. Jean Carnahan and several county clerks in Virginia.