Atlanta-based internet service provider Cox Communications filed a petition Thursday seeking U.S. Supreme Court review of a long-running copyright infringement case that the company said threatens internet access nationwide and carries huge ramifications for Americans and the economy. In the case, music industry groups are seeking to hold Cox responsible for music that was illegally downloaded by subscribers to Cox’s internet service.

The case, if the Supreme Court decides to hear it, could result in a ruling that better defines who bears liability for copyright infringement, how the owners of content are protected and how ISPs police customers’ activity online.

Cox told the high court in its petition for review that if a current appeals court panel ruling stands, imposing liability for the acts of customers of internet providers means such companies would need to terminate service to internet connections “previously used for infringement” or face huge monetary penalties if infringement happens again.

“The question of who is responsible for online copyright infringement carries immense public implications, affecting the interests of rights owners, businesses and users on a pervasive scale,” lawyers for Cox wrote in the petition for cert.

At issue is a 2018 lawsuit filed by record labels asserting that Cox should be held responsible for customers who allegedly committed copyright infringement a decade ago. Record labels filed several similar cases against broadband providers alleging the providers had failed to clamp down on users illegally downloading and sharing music.

At that time, record labels had bet big on selling paid digital downloads and say fighting piracy was key to protecting that emerging business. Today, music streaming services rule the market for digital distribution.

A jury in federal district court ruled in favor of the record companies in 2019 and said Cox failed to adequately prevent its customers from illegally downloading and sharing music.

In February, a federal appeals court panel threw out the $1 billion judgment, ejecting one of the legal claims asserted against Cox because Cox did not profit from the allegedly pirated music. In the ruling, however, the appellate judges upheld another part of the verdict in which the original trial jury found that Cox bore some responsibility for not safeguarding against illegal behavior by its broadband customers.

The appellate panel also sent the case back to district court for a retrial on damages.

Also in February, an attorney for the record companies said the appeals court panel “affirmed the jury’s verdict that Cox is a willful infringer” and said the record labels expected a new jury “to render a significant verdict.”

A message left for a lawyer for the plaintiff record companies was not immediately returned.

Cox Communications is one of the largest internet service providers in the U.S., with millions of customers. It is a subsidiary of Cox Enterprises, which is also the parent company of The Atlanta Journal-Constitution.

Alfred Yen, a law professor at Boston College who studies copyright law and the internet, said the high court could take up this case or similar ones winding through the lower courts. As the internet has evolved, it has left open questions related to who is responsible for abuse of copyright, what level of such infringement is permissible and the remedy for such conduct.

People who infringe copyright are liable for their actions, Yen said. But he said it’s not clear if liability extends to those that do business with them.

Cox is arguing, essentially, that internet service is like a utility, Yen said, noting power companies don’t just cut off electricity because an illegal act might be performed with the help of electricity. A higher level of cause must first exist.

Yen, who said he will likely file what is known as a friend of the court brief in support of Cox’s petition for high court review, said when the internet was founded it was more of a novelty. Today, it has evolved to become an essential piece of global commerce and the way Americans transact many parts of their lives — from their employment to schooling, digital banking to health care.

“The consequences of cutting internet service off are not trivial,” he said.

Still, Yen said ISPs bear some responsibility for illegal activity over its networks, but how much is the question.

And could an internet provider take lesser steps, such as ending a user’s access to a file-sharing service that enables infringement, to stop copyright abuse, he asked.

“In particular, the court needs to say more about when the sale of continued internet service to somebody is unreasonable,” Yen said.

Cox Communications defended its anti-piracy protocols at trial and in its appeal. The company, in its petition to the high court, said fewer than 1% of its millions of users infringed on copyrights and its policies helped curb more than 95% of the abuse that occurred on its networks.

“Imposing liability on providers merely because they continue providing service after receiving allegations of infringement at a given IP address will have dangerous and drastic consequences,” Cox said in its petition. “Grandma will be thrown off the internet because Junior visited and illegally downloaded songs. An entire dorm or corporation will lose internet because a couple of residents or customers infringed. Even with respect to individuals who did, in fact, infringe, loss of internet access is very heavy punishment for illegally downloading two songs. A person without internet might lose their job or have to drop out of school.”

The harm from potential loss of internet access is more acute in areas with fewer providers, Cox argued.

“The consequence is particularly dire for rural subscribers who often have no other ISP option — leaving terminated customers irreparably cut off from society,” lawyers for Cox said in the filing.

Cox said the appeals court panel ruling, if it stands, would have other downstream impacts. Businesses, hospitals, schools and other institutions that offer wireless internet access to the public or their customers would also face disconnection if their users were found to have violated copyright law, Cox said.

Yen said the case also presents concerns about internet privacy if companies face so much liability and risk from wrongdoing done by users of their networks.