German citizens are responsible for the security of their own private wireless connections, a court has ruled.
The ruling comes after a musician sued the owner of a network connection that had been used to illegally download and file-share music.
The owner had proof that the householder was on holiday at the time but the court ruled that the network should have been password-protected.
The court's verdict was that the owner could be fined up to 100 euros (£86).
"Private users are obligated to check whether their wireless connection is adequately secured to the danger of unauthorized third parties abusing it to commit copyright violation," the court in Karlsruhe said.
While it did not find the owner guilty of actual copyright violation the ruling was that the person must take a degree of responsibility for their connection being used to break the law.
British intellectual property barrister David Harris described the verdict as "eccentric".
"I don't think there is any prospect that a UK court would follow that guideline," he told BBC News.
"There is no criminal provision in English law that requires you to secure a wi-fi connection, and currently no liability for the acts of another party if they misuse your connection."
There would be "substantial hurdles" to implementing this judgement in the UK, said Mr Harris.
In a similar case in the UK in 2005, Gregory Straszkiewicz was fined £500 and given a 12 months conditional discharge for using the wireless network of an Ealing resident without permission. The owner of the network was not charged.
However the Digital Economy Bill does suggest that there may be some changes to the law regarding liability in the future, he added.
"Wifi sharing has already subsided because individuals are nervous," said analyst Ian Fogg from Forrester Research.
Even if there isn't a legal issue, there could still be an issue if your broadband provider or package has a limit on how much you can use your connection or terms and conditions about how it should be used."
Initiatives such as Fon, a collaboration between BT and other European ISPs, encourage small businesses and home owners to share their wifi connections in a secure way which separates the activity from the owner to its guest users.