According to the prosecution, the men unleashed a Distributed Denial of Service (DDoS) attack on the website on 5 April 2011, causing its servers to crash and the website to go offline. They also posted up naked pictures of a young actress on the site.
The attack came the day after Norway's Parliament voted to adopt the European Union's controversial Data Retention Directive, which allows member states to store telecommunications data on citizens for up to two years.
Prior to the attack, the web activist group Anonymous had threatened to retaliate if the directive became Norwegian law.
Two of the men are from Elverum, one is from Jessheim and the last is from Flekkefjord. The youngest was only 16 when data attacks occurred .
The Norwegian police on Tuesday declined to comment on whether the four men had documented links to Anonymous.