Story highlights A ruling on the copyright to Superman was decided in part by Facebook ruling

Appeals courts said Warner Bros 2001 deal with creator's family is binding

That's similar to how court ruled in Facebook's battle with Winklevoss twins

Attorney says Superman ruling was "inevitable" because of Facebook

Warner Bros. scored a huge victory in the long-running and byzantine legal battle over the copyright to Superman yesterday, thanks to a ruling by 9th Circuit Court of Appeals that cements the studio's control over the lucrative superhero character.

The decision drew, in part, on precedent established in a lawsuit against Facebook by the Winklevoss twins and held that a 2001 agreement between the heirs of Superman co-creator Jerry Siegel and Warner Bros was indeed binding and that a district judge in a 2008 case had "erred" in granting the Siegel heirs partial copyright.

This decision follows a ruling last October that denied any part of the copyright to the heirs of Superman's other co-creator, Joe Shuster. Shuster and Siegel famously sold their creation to DC Comics for a mere $130 in 1938, long before the character went on to become a multi-billion dollar franchise for the studio, thanks to the success of numerous Hollywood blockbusters, television shows and other merchandise.

The recent ruling on the fate of Superman hinged upon a 2001 agreement between the Siegel heirs and Warner Bros, which the Siegels had claimed was not finalized and therefore not enforceable. In their decision on the case, the 9th Circuit repeatedly cited a lawsuit involving Facebook as precedent, wherein the Winklevoss brothers — who sued the social media site for allegedly stealing their idea -- had similarly claimed that an earlier mediated agreement was non-binding. The court disagreed, and found that under California law, a "term sheet" agreement could be enforceable "even though everyone understood that certain material aspects of the deal would be papered later."

Jeff Trexler , an attorney and law professor who previously served as a clerk in the 9th Circuit, told Wired that while "it's entirely possible that the court would have reached the same outcome without the Facebook ruling... Facebook made it practically inevitable."

Wired reached out for comment to Warner Bros, who responded:

"This is a great day for Superman, for his fans, for DC Entertainment and for Warner Bros. Today's ruling vindicates DC Comics' long-held position that it entered into a binding agreement with the Jerry Siegel family in 2001.The Court's decision paves the way for the Siegels finally to receive the compensation they negotiated for and which DC has been prepared to pay for over a decade. We are extremely pleased that Superman's adventures can continue to be enjoyed across all media platforms worldwide for generations to come."

The decision comes at a fortunate time for the studio, whose new Superman reboot "Man of Steel" heads to theaters in June. Before the latest ruling, Warner Bros. would have been unable to create new "derivative works" based on Superman's first appearance in Action Comics #1 — presumably including Superman films — without accounting for the profits to the Siegels as co-owners, complicating plans for a potential Man of Steel sequel and the Justice League movie slated for 2015.

Now, Warner Bros. will likely be able to proceed without further hindrance, ending a nearly 65-year legal battle whose uglier moments included a letter from Siegel's dying widow (the original model for Lois Lane) accusing the Warner Bros. lawyers of harassment and a still-ongoing lawsuit by Warner Bros. accusing the Siegel's lawyer Marc Toberoff of misconduct.