Norway's data protection department has indicated that ISPs must delete all personal IP address-related data just 3 weeks after collection. The instruction, initially given to two ISPs but applicable to them all, means that it will be incredibly difficult to take action against file-sharers.

Previously it hasn’t been particularly easy for copyright holders to go after alleged infringers in Norway, but just recently the country’s telecoms regulator said that file-sharers’ identities can be given to copyright holders, providing a court agrees there is a good reason to hand them over. This means that these individuals can be pursued through the courts, or through “pay up or else” type threats.

However, the authority in charge of data protection in Norway has just made that process much, much harder for the copyright holders, since it has instructed two ISPs – Tele2 and Lyse Tele – to delete all IP address-related personal information they hold on their customers which is more than 3 weeks old.

According to Aftenposten the decision, borne of the Personal Data Act which prohibits the storage of unnecessary data, will apply to all ISPs in Norway such as Canal Digital, NextGenTel, Telenor and others.

The fact that data can only be held for just 21 days will see the immediate deletion of IP information held on around 1.6 million subscribers by these Norwegian ISPs. However, the decision flies in the face of European Union rules which say that this type of data must be held for at least 6 months – right now in Norway, data retention can be anything from a few days to five months.

The process of monitoring file-sharers, gathering evidence and then collating it all into an acceptable format can be time consuming. Add this to the time taken to get into the system to obtain a court order from a judge to force the ISPs to hand over data on their customers, and you end up with a period longer than 21 days. By which time the data has gone and the evidence becomes useless, since it’s impossible to identity the alleged infringer.

Movie industry lawyer Espen Tondel isn’t going to like this, one little bit.