Holger Voss, who last month argued in court that dynamic IP addresses are irrelevant for book keeping and shouldn't be stored by ISPs, has won part of his case against German ISP T-Online.

A court in Darmstadt has ruled that it is perfectly legal for a provider to store data on its users (such as logon times or the amount of megabytes sent or received), as they are important in billing arguments. However, storing IP addresses as such is a violation of the German law, the court agreed.

According to the German Tele Services Data Protection and Telecommunications Act, ISPs are only allowed to store communications data for accounting purposes. Although Voss didn't deny that the storage of IP addresses has a purpose, he argued that storage is total irrelevant in his case: Voss has a flat fee subscription.

The ruling may turn out to be unworkable for ISPs: how do you keep logs without the corresponding IP address? However, in a related case, ISP Lycos decided to simply no longer store dynamic IP addresses of its customers after a specialist on data privacy laws had threatened to sue the company.®

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