Legal analysts say a federal judge's ruling absolving a Web site of responsibility for the posting of copyrighted video clips without their owner's consent could be a good sign for YouTube and other video-sharing services.

On Wednesday, U.S. Magistrate Judge Howard Lloyd tossed out a copyright infringement lawsuit filed by adult video maker Io Group Inc. against Veoh Networks Inc., a Web site that streams ad-supported shows. The pornography company sued Veoh in June 2006 after it said it discovered 10 of its clips posted on the site without permission.

Lloyd ruled that Veoh complied with federal law by promptly taking down the videos after being informed the clips were posted without permission.

In a similar lawsuit, media giant Viacom Inc. is suing Google Inc.'s YouTube for $1 billion, alleging that YouTube's popularity is based on impermissible use of copyrighted material such as Comedy Central's "The Daily Show with Jon Stewart" and Nickelodeon's "SpongeBob SquarePants" cartoon.

"This ruling is a big boost for YouTube," said Fred von Lohmann, an attorney with the Electronic Frontier Foundation, an advocacy group that specializes in Internet civil liberties issues. Von Lohmann said that at least a dozen other video-hosting Web sites facing similar legal challenges should also be helped by the ruling.

"Once content has been identified as infringing, Veoh's digital fingerprint technology also prevents the same infringing content from ever being uploaded again," the judge wrote in his decision. "All of this indicates that Veoh has taken steps to reduce, not foster, the incidence of copyright infringement on its Web site."