The Supreme Court on May 13 partly upheld a 1998 law intended to shield children from online pornography, but said there are unresolved free-speech questions that prevent the law from taking effect now.

The American Civil Liberties Union (ACLU) had challenged the Child Online Protection Act as unconstitutional, claiming that in protecting children, the law also violates the rights of adults to see or buy what they want on the internet.

A divided Supreme Court said the law's use of what it calls "community standards" to define what is harmful to children does not by itself make the law unconstitutional, as a lower federal appeals court ruled.

But the court went on to say there are other potential constitutional problems with the law that were not addressed by the lower court. Without taking a position on those other potential problems, the high court threw out the lower court's ruling and sent the case back for further review.

The high court's action means the 1998 law is still on hold, and the government is barred from enforcing it.

The ruling is a partial victory for the Bush administration, but neither side got what it really wanted.

The law, known as COPA, makes it a crime for commercial operations to knowingly place objectionable material within easy reach of children on the internet. Violators may be fined up to $50,000 and sentenced to six months in jail.

The law also requires adults to use access codes and or other ways of registering before they could see objectionable material online.

COPA is different from the Children's Internet Protection Act, or CIPA, which Congress passed in 2000. CIPA requires schools and libraries receiving federal technology funding to install filters on computers used by children. A federal court in Philadelphia is weighing the constitutionality of CIPA.

The ACLU challenged COPA on behalf of artists, sex therapists, and others who post legitimate, if risque, material on the World Wide Web.

Eight justices agreed that the case should be sent back to the 3rd U.S. Circuit Court of Appeals for a closer look, although they differed in their reasons. Only Justice John Paul Stevens dissented.

"The scope of our decision today is quite limited," Justice Clarence Thomas wrote for a five-member court majority. "We hold only that COPA's reliance on community standards to identify 'material that is harmful to minors' does not by itself render the statute substantially overbroad," Thomas wrote.

He pointedly said the court would take no position on the ACLU's claims that the law is unconstitutionally broad and vague for reasons apart from community standards.

"Prudence dictates allowing the court of appeals to first examine these difficult issues," Thomas wrote.

Stevens said the appeals court acted correctly, and that the entire law should be struck down as unconstitutional.