SAN JOSE, Calif. - A manufacturer of electronic voting equipment knowingly misrepresented its claims when it sent threatening letters to the Internet providers of people who had posted the company's internal documents online, a federal judge has ruled.

Diebold Inc.'s letters claimed the leaked documents violated its copyrights under the Digital Millenium Copyright Act and demanded that they be removed immediately. But the same law bars making threats when the copyright holder knows no infringement occurred.

On Thursday, U.S. District Judge Jeremy Fogel issued a summary judgment in favor two Swarthmore college students, who posted the material, and their Internet provider Online Privacy Group, which declined to comply with Diebold's demands.

They sued Diebold in November 2003, seeking $5,185.50 in damages and attorneys' fees. Fogel will determine the amount of damages to be awarded at a later time.

"This decision is a victory for free speech and for transparency in discussions of electronic voting technology," said Wendy Seltzer, an Electronic Frontiers Foundation attorney who represented OPG in the case.

David Bear, a spokesman for North Canton, Ohio-based Diebold, said the company was still reviewing the ruling and would not comment until it had done so. In December, the company said it would not sue anyone who posted the documents.

Electronic voting has come under attack by activists who fear the equipment is vulnerable to hacking, software bugs and hardware failures.

In March 2003, a hacker broke into Diebold's servers using an employee's ID number, and copied a 1.8-gigabyte file of company announcements, software bulletins and internal e-mails dating to January 1999.

The vast majority of the file included banal employee e-mails, software manuals and old voter record files. But several items seemed to reinforce concerns about electronic voting that advocates had been trying to publicize for more than a year.

Diebold responded by sending dozens of cease-and-desist orders to people who had posted the documents and their Internet providers.

In his ruling, Fogel disagreed with the company's legal claims.

"No reasonable copyright holder could have believed that the portions of the e-mail archive discussing possible technical problems with Diebold's voting machines were protected by copyright," he wrote.

The decision also has implications for people who receive so-called takedown letters on matters outside the current e-voting debate, said Will Doherty, OPG's executive director.

"This ruling means that we have legal recourse to protect ourselves and our clients when we are sent misleading or abusive takedown notices."