(PHILADELPHIA, PA) -- A federal appeals court ruled the U.S. government's latest bid to restrict Internet pornography unconstitutional on Thursday, dealing a fresh blow to congressional efforts to protect minors from online smut.

In a unanimous decision, a three-judge panel of the 3rd U.S. Circuit Court of Appeals reluctantly upheld an earlier ruling by a lower court judge who found that the Child Online Protection Act violated the First Amendment right to free speech.

Appeals court Judge Leonard Garth described the government's intention to protect minors as ``laudatory'' in a 33-page opinion that echoed the words of U.S. District Judge Lowell Reed, who imposed an injunction against the law in February 1999.

``Sometimes we must make decisions that we do not like,'' he said. ``We make them because they are right, right in the sense that the law and the Constitution, as we see them, compel the result.''

COPA, which was enacted by Congress and signed by President Clinton in 1998, would prevent minors from accessing pornographic sites on the World Wide Web by requiring commercial site operators to impose electronic proof-of-age barriers.

Violators would face up to six months in prison and $50,000 in fines for each violation.

But the new law quickly ran into a federal court challenge from the American Civil Liberties Union (ACLU) and 17 plaintiffs, including online magazine publishers, booksellers and gay rights organizations.

Reed imposed an injunction to stop the law from taking effect, saying it violated the First Amendment right to free speech, partly because site operators had no effective means of screening out minors.

After hearing arguments last November, the 3rd Circuit appellate panel noted that Web site operators would also be unable to determine the geographic location of site visitors using a worldwide computer network.

``What it really illustrates is how totally unconstitutional this law was,'' said Chris Hansen, senior staff counsel with the ACLU.

``This suggests it may be difficult for Congress if they want to try yet again to craft a constitutionally acceptable law.''

Members of Congress had hoped the law would succeed where its predecessor, the Communications Decency Act, failed. That earlier piece of legislation, which had sought to prevent all Internet users from distributing pornography to minors, was struck down in 1997 by the U.S. Supreme Court.

Rep. Michael Oxley, the Ohio Republican who authored much of COPA, was not available for comment.

A spokeswoman for the Justice Department, which argued the case for the government, said the ruling was under review and ''appropriate action'' would be taken.