MOUNTAIN VIEW, Calif. — A hearing in which lawyers for Google were to defend the company’s refusal to hand over search engine data in the Justice Department’s anti-porn crusade has been moved to March 13, more than two weeks from when it was initially scheduled.

U.S. District Court Judge James Ware gave no explanation for the postponement on Thursday.

At the center of the hearing will be whether Google must comply with a Justice Department subpoena, sent to the company more than a year ago, which demands the search engine hand over mountains of data detailing what its users search for while online.

Representatives at the Justice Department have claimed the information will aid the government with new child porn legislation expected to hit Washington later this year, but the requests also have touched off a number of privacy concerns, with many opponents arguing that the type of information someone searches for on the Internet defines the user’s personality, and is therefore an invasion of privacy, regardless of whether or not the individual is personally identified.

Privacy groups also have theorized that the initial request by the government, though relatively innocuous, could lead to larger invasions.

At the same time that Google battles free speech and privacy issues at home, however, the company quietly acquiesced to Chinese demands to heavily filter the new Google China, which launched in late January.

Filters embedded in Google.cn include a long list of banned terms, including not only words related to pornography and online fraud, but also to “democracy,” “June 4, 1989,” “Falun Gong” and “independence.”

A search for “June 4, 1989,” on the U.S.-version of Google, for example, brings up a number of articles on the 1989 crackdown that ended the Tiananmen Square pro-democracy movement. The same search on the Chinese-version of Google yields no mention of the incident.