The European Court of Justice ruled against Spanish music rights holders association Promusicae and in favor of Spain’s’ largest telecom operator Telefonica. Telefonica maintained that under a national law based on EU rules, it only had to release the name of an Internet subscriber for criminal actions, not civil ones.

"Community law does not require the member states, in order to ensure the effective protection of copyright, to lay down an obligation to disclose personal data in the context of civil proceedings," the court said.

Promusicae requested the names of Telefonica Internet users who shared copyright material on the Internet using the KaZaA file exchange software so it could bring civil suits against them.

Civil proceedings are less expensive than criminal proceedings, which require a higher burden of proof.

"There are several community directives whose purpose is that the member states should ensure, especially in the information society, effective protection of industrial property, in particular copyright," the court said.

"Such protection cannot, however, affect the requirements of the protection of personal data. The directives on the protection of personal data also allow the member states to provide for exceptions to the obligation to guarantee the confidentiality of traffic data."