Shohei Miyano / REUTERS

Media giant Viacom just can’t win — at least when it comes to the company’s long-running, landmark copyright infringement lawsuit against Google‘s YouTube video service. A federal judge handed a major victory to YouTube on Thursday, one year after a federal appeals court breathed new life into Viacom’s $1 billion lawsuit. Viacom had accused YouTube of illegally hosting videos that infringe on the company’s intellectual property, including popular content like MTV videos and TV shows like Comedy Central’s “South Park.”

U.S. District Judge Louis Stanton, who has presided over the case for several years, once again found that Google and YouTube are protected by the “safe harbor” provisions of the Digital Millennium Copyright Act, a 1998 law that limits the liability of websites if they remove content when notified of possible copyright violations. Last year, a federal appeals court revived the case, extending one of the most important Internet intellectual property disputes of the last decade. The case became a flash point in the ongoing struggle over intellectual property between big entertainment companies like Viacom and internet giants like Google and YouTube.

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“The ruling is a great victory for YouTube,” Eric Goldman, director of the High Tech Law Institute at Santa Clara University School of Law, told TIME. “The judge emphatically rejected all of Viacom’s arguments, as well as its spin on the facts. Given that Viacom has made no real progress in this case after 6 years of litigating, the judge’s ruling reinforces how the entire lawsuit has been a waste of time and resources for everyone concerned.”

Viacom sued YouTube in March 2007, less than a year after Google purchased YouTube for $1.65 billion. In its lawsuit, Viacom argued that YouTube’s explosive growth was based, in part, on users posting videos of Viacom’s programs, including South Park and The Daily Show. In its defense, Google argued that the DMCA protected YouTube from liability because the site promptly takes down infringing content once it is notified. According to the DMCA, safe harbor protection applies if an Internet service provider like YouTube “responds expeditiously to remove, or disable access to, the material that is claimed to be infringing.”

Google hailed Thursday’s ruling. “The court correctly rejected Viacom’s lawsuit against YouTube, reaffirming that Congress got it right when it comes to copyright on the Internet,” Kent Walker, Google’s general counsel, said in a statement to TIME. “This is a win not just for YouTube, but for people everywhere who depend on the Internet to exchange ideas and information.”

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But Viacom isn’t taking this latest defeat sitting down. “This ruling ignores the opinions of the higher courts and completely disregards the rights of creative artists,” company spokesman Jeremy Zweig said in an email to TIME. “A jury should weigh the facts of this case and the overwhelming evidence that YouTube willfully infringed on our rights.” The company said that it would once again appeal the ruling.

“At this point, I don’t have any idea why Viacom continues to press its point,” Goldman said. “I guess copyright owners are persistent. By 2010, Google had already spent $100 million defending this case. Lord knows how many more millions of dollars the parties have spent since then.”

Last year’s decision in favor of Viacom was a big loss for YouTube. In its ruling, the 2nd U.S. Circuit Court of Appeals in New York affirmed that the “safe harbor” provision of the Digital Millennium Copyright Act (DMCA) protects online companies like YouTube from liability as long as they promptly remove infringing content upon notification. But the panel raised questions about whether YouTube had specific knowledge that such content existed on their site.

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“We conclude that the District Court correctly held that [the safe harbor] requires knowledge or awareness of specific infringing activity,” the court wrote, “but we vacate the order granting summary judgment because a reasonable jury could find that YouTube had actual knowledge or awareness of specific infringing activity on its website.”

In his original ruling, Judge Stanton found that “general knowledge that infringement is ‘ubiquitous’ does not impose a duty on the service provider to monitor or search its service for infringements.” That was a victory for Internet companies because it rejected an argument frequently advanced by Viacom and other big content companies that websites must take a more proactive role in policing their sites in order to earn DMCA protection. Currently, the burden lies on content companies to notify websites of infringing material.

But the appeals court ruled that if YouTube executives had “actual knowledge or red flag awareness” of specific examples of copyright infringement — or demonstrated “willful blindness” by not moving to remove infringing material as its growth skyrocketed — the company may lose its safe harbor protection. In Thursday’s decision, Stanton once again rejected Viacom’s position that YouTube didn’t deserve DMCA protection.