The Justice Department has asked a federal judge to compel Google, the Internet search giant, to turn over records on millions of its users' search queries as part of the government's effort to uphold an online pornography law.

Google has been refusing the request since a subpoena was first issued last August, even as three of its competitors agreed to provide information, according to court documents made public this week. Google asserts that the request is unnecessary, overly broad, would be onerous to comply with, would jeopardize its trade secrets and could expose identifying information about its users.

The dispute with Google comes as the government is moving aggressively on several fronts to obtain data on Internet activity to achieve its law enforcement goals, from domestic security to the prosecution of online crime. Under the antiterrorism law known as the USA Patriot Act, for example, the Justice Department has demanded records on library patrons' Internet use...

Charles Miller, a spokesman for the Justice Department, said on Thursday that three Google competitors in Internet search technology - America Online, Yahoo and MSN, Microsoft's online service - had complied with subpoenas in the case...

In its brief history, Google has made "Don't be evil" an operating principle...