A 35-year-old Dutchman was arrested Thursday in Spain, as part of an investigation into a large-scale DDoS attack that targeted a spam-fighting organization in March. The suspect was arrested by Spanish authorities in Barcelona based on a European arrest warrant. He is expected to be transferred to the Netherlands soon, the Dutch Public Prosecution Service says. A group called the Stophaus Movement, whose members include companies and individuals flagged as spammers by Spamhaus, took credit for the attack. A source familiar with the investigation says the man arrested is Sven Kamphuis, who acted as a spokesman.”]