The Justice Department wants Google to turn over information on how millions of Americans use the Internet, but the search engine giant has vowed to fight the demand.
Attorney General Alberto Gonzalez filed the motion Wednesday in district court near Google's headquarters in San Jose, Calif., seeking the data to help the government defend the Child Online Protection Act.
The law would restrict the posting of sexually explicit material on commercial Web sites unless it is "unavailable" to minors. The courts have suggested that pornography filters would be more effective. The government wants to use Google's information to build a case against filters and for restricted access to pornography.
Court documents obtained by ABC News show the government is not after personal information. It wants Google to produce a sample of 1 million random Web sites, as well as Web addresses of all Google searches for a one-week period. Other search engine providers have cooperated with the government.
The data could not be used to trace the searches of individual Google users, but privacy advocates are nevertheless concerned.
"It's not an issue of privacy but it raises the question that next time it could be," said Web search expert Danny Sullivan.
"If the government wants to estimate how much pornography shows up in the searches, then they are asking for data that is useless to them," said Sullivan. "You can get that information from other companies." Several companies sell similar data.
Privacy advocates have long feared misuse of data compiled by search engine companies like Google.
Search engines typically keep data on search terms, Web sites visited and the electronic addresses of users. They also use "cookies" -- tiny files stored on users' hard drives -- to keep track of their repeat visits to search engine sites. It's a massive store of data that tracks online behavior.
Google says it uses the information to constantly improve services, but now its existence has prompted the government's lawsuit. "If they didn't keep and store this data they wouldn't be in this bind," says Sherwin Siy of the Electronic Privacy Information Center. "It highlights the potential for misuse, whether it's unreasonable search and seizure by the government or sale of the information to private companies."
Google says it does not sell user information and the government isn't asking for that data. Still, the company claims the government request "overreaches." Experts say it would take considerable resources to comply with the government's request and it's unclear whether such data would be useful. Complying could hurt Google in other ways, they add.
"It would jeopardize Goggle's position with its competitors and compromise relations with users," said Sullivan.