A rough translation of http://tweakers.net/nieuws/71263/anonymous-legt-site-openbaar-ministerie-plat-na-arrestatie.html (Dutch) :
“A group of people operating under the moniker ‘Anonymous’ has successfully attacked the website of the Dutch public prosecutors office as well as the site of the dutch police which was running on the same server.
This was apparently in response the arrest of the 16 year old boy from Zoetermeer in response to the attack on Mastercard.com.
In the meantime the site is sporadically accessible again.
The 16 year old that was arrested on Thursday was operating under the pseudonym Jeroenz0r en lives in Zoetermeer. He was one of the operators of the IRC-channel which sympathizers of wikileaks used to coordinate their attacks.
The distributed denial of service attacks are being organised from IRC under the motto “operation payback”.
The attacks are aimed at the websites of companies and organizations that block WikiLeaks or otherwise hinder it. Amongst others, Mastercard, Visa, Amazon and others were attacked. Because of the small size of the attacks they did not all succeed.
The exact number of bots which is being used is unclear, but seems to fluctuate according to estimates between 75,000 and 100,000. Meanwhile the activists are searching for ways to avoid people like Jeroenz0r from being traced. They’re currently looking at p2p technology in order to achieve tihs.
It is unclear whether or not the dutch authorities are looking at more suspects. At a minimum one other Dutch national was involved in the attacks on mastercard.com”