SACREMENTO, Calif. — A district court judge has dismissed a copyright infringement lawsuit against Napster Inc., stating, in essence, that simply making a copyrighted file available on a file-sharing network does not constitute infringement.

The upshot is that Judge Marilyn Patel’s decision contradicts early media interpretations of the recently passed Artists’ Rights of Theft Prevention Act of 2005, which was seen as lowering the bar for online copyright prosecutions.

The ART Act, signed into law last month, established criminal penalties of up to three years in prison and hundreds of thousands of dollars in fines for the distribution of "pre-released" movies over the Internet.

At the time of the law’s passage, it was widely interpreted to mean that leaving files open in shared or exposed folders would be enough to prosecute peer-to-peer network operators, regardless of whether any files were downloaded.

This is the argument that plaintiffs in the case, which included UMG Recordings Inc., used in their motion against Napster — that simply making a file available for distribution should be considered an infringing act and that websites that offer such files for download should be held criminally liable for copyright violations.

But in her three-page dismissal order, Patel said she found the plaintiffs’ argument unconvincing because they failed to show evidence of distribution.

Patel went on to say that despite media speculation to the contrary, the language of the ART Act actually makes a clear distinction between “making available” something for distribution and the act of distributing it, and that the plaintiffs conveniently disregarded that language in their abstract.

If Congress had intended to make it a criminal offense to leave files open for download on P2P networks, Patel pointed out, they should have and could have explicitly done so in the language of the law.

Yale Law School fellow Ernest Miller said Patel’s decision could have far-reaching consequences for defense against prosecution under the ART Act.