A federal lawsuit filed in Massachusetts could test the question of whether individuals who leave their wireless networks unsecured can be held liable if someone uses the network to illegally download copyrighted content.

The lawsuit was filed by Liberty Media Holdings LLC, a San Diego producer of adult content.

The company has accused more than 50 Massachusetts people, both named and unnamed, of using BitTorrent file-sharing technology to illegally download and share a gay porn movie.

According to the compliant, the illegal downloads and sharing were traced to IP addresses belonging to the individuals named in the compliant and to several John Does. The complaint alleges that each of the defendants either was directly responsible for downloading and sharing the movie or contributed to the piracy through their negligence.

Even if the defendants did not directly download the movies, they had control over the Internet access used for copyright infringement purposes, the lawsuit noted.

"Defendants failed to adequately secure their Internet access, whether accessible only through their computer when physically connected to an Internet router or accessible to many computers by use of a wireless router," Liberty Media claimed. "Defendants' negligent actions allowed others to unlawfully copy and share Plaintiff's copyrighted Motion Picture, proximately causing financial harm to Plaintiff and unlawfully interfering with Plaintiff's exclusive rights in the Motion Picture."

The lawsuit seeks either actual or statutory damages from each of the defendants.

Marvin Cable, a Northampton, Mass.-based attorney for two of the defendants in the case, said, "this negligence theory is a novel one," both in Massachusetts and around the country. He predicted that Liberty Media will have a hard time making its argument, because there is no case law or statutory basis for the negligence claims.

If the company were to prevail, the case could have broad implications for those who provide free Internet access in places such as libraries, cafes, airports and schools, Cable said.

Marc Randazza, general counsel for Liberty Media, described the negligence claims as a new legal theory that the courts will need to weigh in on.

He pointed to a 1932 case in which the owners of two tugs boats were found liable for cargo that was lost when two barges they were towing were sunk in a storm. The plaintiffs in that case alleged that the tugboat owners were negligent because they had failed to install radios, which would have alerted them to the storm.

Though tugboats were not legally obliged to have a radio on board at that time, an appellate court held that the owners were negligent nonetheless for having failed to have one on board the tugboats.

The same standard needs to apply to owners of unsecured wireless access points, he said. This is how common law develops, Randazza said. You should know better than to leave your home wireless open."

In general, to bring a negligence claim a plaintiff has to show that the defendants had a duty to perform, that they breached that duty and that the breach resulted in actual harm, he said.

Randazza added that businesses and others offering Internet access as a service are already legally immune from the action of users on their networks.

Jaikumar Vijayan covers data security and privacy issues, financial services security and e-voting for Computerworld. Follow Jaikumar on Twitter at @jaivijayan or subscribe to Jaikumar's RSS feed . His e-mail address is jvijayan@computerworld.com.