A crucial ruling in one of the ongoing BitTorrent lawsuits in the United States has delivered a clear win for open Wi-Fi operators. Among other things, California Judge Phyllis Hamilton ruled that Internet subscribers are not required to secure their wireless networks to prevent outsiders from pirating movies. In other words, people can't be held liable for the alleged infringements of other people on their network.

BitTorrent lawsuits have been dragging on for more than two years in the US, involving more than a quarter million alleged illicit file-sharers.

The copyright holders who start these cases generally provide nothing more than an IP-address as evidence. They then ask the courts to grant a subpoena which allows them to request the personal details of the alleged offenders from their Internet providers.

The problem with this scheme, however, is that the person who pays the Internet bills may not be the person who pirating the movie or song in question. Several judges have noted that an IP-address is not a person, much to the disappointment of copyright holders.

To counter this argument copyright holders have introduced the “negligence” theory, arguing that Internet subscribers are liable when other people pirate files through their networks. This would allow copyright holders to sue people even when their targets haven’t committed an offense.

One of these cases was decided last week in favor of the Internet subscriber.

The case was started by adult video company AF Holdings who sued an Internet account holder called Josh Hatfield in a California federal court. AF Holdings claimed that Hatfield had a “duty to secure his Internet connection,” and that he “breached that duty by failing to secure his Internet connection.”

As a result, AF Holdings argued that Hatfield was liable for the copyright infringements that were committed by an unknown person. Mr. Hatfield disagreed with this claim, and argued that the copyright holder couldn’t prove that people are obliged to secure their wireless networks to prevent piracy.

In her verdict Judge Phyllis Hamilton sided with the defendant.

“AF Holdings has not articulated any basis for imposing on Hatfield a legal duty to prevent the infringement of AF Holdings’ copyrighted works, and the court is aware of none,” Hamilton writes.

“Hatfield is not alleged to have any special relationship with AF Holdings that would give rise to a duty to protect AF Holdings’ copyrights, and is also not alleged to have engaged in any misfeasance by which he created a risk of peril,” she adds.

In addition to this lack of duty of care, Judge Hamilton ruled that even if negligence could be proven then “personal injury” state law would be preempted by federal copyright law.

The ruling in the current case is similar to that of Judge Lewis Kaplan in New York earlier this year although perhaps even stronger – Judge Hamilton specifically rules that Internet subscribers don’t have an obligation towards copyright holders to secure their Wi-Fi.

The Electronic Frontier Foundation (EFF), who have helped out many alleged BitTorrent pirates over the years, are happy with the outcome.

“This ruling, along with the Tabora ruling in New York, send a strong judicial message that copyright owners can’t use legal tricks to bypass the law’s protections for Internet access points,” EFF’s Mitch Stolz writes.

“There are still many open cases in the federal courts where copyright owners are trying to use this bogus legal theory,” he adds.

The ruling is definitely a setback for the many copyright holders who jumped aboard the lucrative BitTorrent lawsuit bandwagon. Should more judges reach the same conclusion in future cases the end of this type of lawsuit in the U.S. may very well be near.