A judge told Dutch cable operator and Internet broadband provider UPC, a unit of Liberty Global, to give the name and address of one its clients to an anti-piracy agency, according to a Reuters report.
The Reuters report said the result is a breakthrough for Dutch copyright holders interest group Brein, which has long tried to gain access to names and addresses of individuals who it suspects of swapping large numbers of songs, films and other copyrighted material.
Lawyers said it is the first time a Dutch Internet service provider will have to hand over personal details of file swappers who store copyrighted content on their own computers, the report said.
UPC said it had always refused to supply subscriber data because this would be a breach of Dutch privacy laws, according to the report.
But the Amsterdam judge said that privacy rules did not apply if two conditions were met: copyright holders needed to prove, beyond reasonable doubt, that files had been swapped illegally, and also that the person swapping the files was the same person who was the registered customer.
The report further said UPC would consider its position after the ruling in the summary proceedings.