Google has argued that turning over more than a million of its search records to the U.S. government would undermine users' trust in its service and compromise its trade secrets.
Arguing against a government subpoena that seeks a week's worth of search data from the company, Google also argued that the request places an undue burden on it and asked the district court in San Jose, California, to reject the government's motion forcing Google to comply.
"Google users trust that when they enter a search query into a Google search box, not only will they receive back the most relevant results, but that Google will keep private whatever information users communicate absent a compelling reason," the company's lawyers wrote in court papers filed Friday.
"The Government's demand for disclosure of untold millions of search queries submitted by Google users and for production of a million Web page addresses or 'URLs' randomly selected from Google's proprietary index would undermine that trust, unnecessarily burden Google, and do nothing to further the Government's case in the underlying action."
The U.S. Department of Justice (DOJ) requested the information in August last year. It says it wants it to use in a separate case, to help determine whether a federal law called the Child Online Protection Act (COPA) is more effective than filtering software in preventing minors from accessing harmful material on the Internet.
Yahoo, Microsoft's MSN division and America Online were issued with similar subpoenas and all complied with the request to some degree. The government says the search data is not tied to individual users and will not reveal people's individual search habits.
The request for data comes at a sensitive time for the four search companies. Last week, members of the U.S. House of Representatives branded them a "disgrace" for allowing the Chinese government to censor content from their services. The search giants have said their actions are part of doing business in countries with restrictive laws, and that even a modified version of their service will help to encourage free speech.
The DOJ has until Feb. 24 to respond to Google's arguments. A hearing in the case, brought by U.S. Attorney General Alberto Gonzales, is set for March 14.
The DOJ did not issue a response to Google's latest arguments and could not be reached for comment Monday, a public holiday in the U.S.
The DOJ is defending COPA in a 1998 suit filed by the American Civil Liberties Union, which says the law violates the U.S. Constitution's First Amendment right to freedom of speech.
The DOJ says the search records from Google and its peers will help it to prove that filtering technologies are not an effective way to prevent minors from accessing harmful content. The ACLU says that they are.
In its court papers Friday, Google said it uses confidential methodologies and algorithms to arrive at its search results. The government's experts would have to study these techniques to make its search data useful to them, and this would put the company's trade secrets at risk, it said.
"Competition with Google is fierce. Google's competitors could use Google's confidential query data to manipulate their search engines to accommodate Web users and run queries similar to Google's," its lawyers wrote.
They argued that the government has fallen "woefully short" of showing that the search data will be of any use to it, calling some of its reasoning "so uninformed as to be nonsensical."
People sometimes filter their search results using Google's built-in pornography filter or by creating "advanced queries." That means the same query could generate different results, making the data misleading and unhelpful to the government, the company said.
Searches performed by Web bots and by people who run the same query repeatedly to check their search ranking can also skew the results, the company said.
To protest the government's subpoena, one person even wrote a program for the Firefox Web browser that sends a random pornography query to Google every time a user enters a query, in a bid to skew Google's search records, the company said.
The ACLU's challenge to the COPA laws has so far been successful. The Pennsylvania court in which the lawsuit was filed granted the ACLU's motion for a preliminary injunction, and an appeals court affirmed it in 2000.
The case went to the U.S. Supreme Court, which eventually also affirmed the preliminary injunction and sent the case back to the lower courts for a trial. The government and the ACLU are now preparing for that trial.