Fatwa on Salafvoice
On December 24, 2008, the Islamic website Salafvoice was asked a question about hacking: "I am working on hacking websites which defame Islam, and because these websites contain security measures, they force you to enter a username and password on one of the websites. What is the ruling on this matter?"
The answer given was: "The destruction of websites which are offensive to Islam is a duty for all who are able, with the help of Allah."
May 9, 2013