San Francisco ? Google Inc. is rebuffing the Bush administration’s demand for a peek at what millions of people have been looking up on the Internet’s leading search engine – a request that underscores the potential for online databases to become tools for government surveillance.

Mountain View-based Google has refused to comply with a White House subpoena first issued last summer, prompting U.S. Atty. Gen. Alberto Gonzales this week to ask a federal judge in San Jose for an order to hand over the requested records.

The government wants a list of all requests entered into Google’s search engine during an unspecified single week – a breakdown that could conceivably span tens of millions of queries. In addition, it seeks 1 million randomly selected Web addresses from various Google databases.

In court papers, the Bush administration depicts the information as vital in its effort to restore online child protection laws that have been struck down by the U.S. Supreme Court.

Yahoo Inc., which runs the Internet’s second-most used search engine behind Google, confirmed Thursday that it had complied with a similar government subpoena.

Although the government says it isn’t seeking any data that ties personal information to search requests, the subpoena still raises serious privacy concerns, experts said.