In a case that has gone on for years, Germany’s highest court further reduced the legal responsibilities of Internet connection owners when it ruled Wednesday that parents are in principle not liable if their adult children use the family Internet connection for file sharing.

The decision follows a November 2012 verdict in which the same court, the Federal Court of Justice, ruled that parents are not liable for their minor’s file sharing, as long as they warned their child that unauthorized downloading and sharing of copyrighted material online is illegal and they were unaware their child violated this prohibition.

However, when children are adults, parents don’t have to warn them in order to avoid liability, the Federal Court of Justice ruled Wednesday. In Germany, the age of majority is 18.

In the case before the Federal Court of Justice, four German record producers sued the owner of an Internet connection that was used in 2006 to make 3,749 copyright protected music recordings available for download on the Internet via a file sharing network, the court said.

The songs were shared by the then 20-year-old stepson of the man who owned the Internet connection, the court said in a news release. The record companies however tried to recover €3,454 (about US$4,700) in damages from the stepfather who owned the connection, rather than from the stepson. While the stepfather signed an agreement that his Internet connection would not be used for that purpose again, he refused to pay, saying that he was not liable for his stepson’s deeds, the court said.

Even so, the Regional Court of Cologne in 2010, and subsequently the Higher Regional Court of Cologne in 2011, ruled that the stepfather was liable for the copyright infringement. He was ordered to pay €2,841 to the record companies by the Higher Regional Court.

By making the Internet available to his stepson, the stepfather created the opportunity for him to take part in illegal online file sharing, the Higher Regional Court reasoned. Because this risk was there, it would have been reasonable to expect that the stepfather would have educated his stepson on the illegality of online sharing of copyright protected material and prohibited him to use file-sharing programs, even without having concrete evidence his stepson was doing this or interested in doing this, the Higher Regional Court said at the time.

Because the stepfather had violated this obligation he was liable, the Higher Regional Court ruled.

But the German Federal Court of Justice disagreed.

Adults are responsible for their own actions, the court said. Moreover, the owner of the Internet connection should be able to let his adult family members use the Internet without having to teach them first or monitor their behavior, it added.

Only if the owner of the Internet connection has a specific reason to suspect that family members are using the connection for rights violations, should he take the necessary measures to prevent infringements, the court said.

Since there is no evidence the stepfather had such suspicions, he is not liable for his stepson’s infringements, the court ruled. He would also not have been liable if he did not, or did not sufficiently, inform his stepson of the illegality of participating in file-sharing networks, the court added.

The stepfather could be liable only if the stepson used the Internet connection for copyright violations, his stepfather knew about it and did nothing to prevent it, said Karin Milger, a judge and spokeswoman for the Federal Court of Justice who was not part of the judges panel in the case.

The ruling doesn’t mean that the stepson now has to pay the compensation demanded by the record companies, she said. They could however decide to sue the stepson because he did violate the rights of the copyright holders, she added.

As is customary in Germany, the names of those involved in the case were not divulged for privacy reasons.