Nevertheless, the case is considered a crucial barometer of how much control a search engine has over its vault of Web traffic and whether the Internet habits of its users are insulated by a 20-year-old electronic privacy law. Orin Kerr, a law professor at George Washington University, said that if the government gets the information, it's conceivable Congress may eventually step in with legislation that would prevent the broad release of data collected on Internet searches.

``The subpoena was a wake-up call to everybody that search engines have these logs and can produce them,'' added Kevin Bankston, a lawyer with the Electronic Frontier Foundation, which opposes the release of the data. ``By storing all this data in perpetuity, they are creating a honey pot, not only for the government but for civil litigants'' who seek it for a host of reasons, from divorce fights to feuds between rival companies.

Justice Department lawyers declined comment on the case, but in court papers argue that Google and its supporters have overstated the risks of releasing the information. Government lawyers stress that the data they seek would not identify individual users.