Dozens of grass roots anti-nuclear groups across Japan have been targeted in a cyberattack that swamped inboxes with more than 2.5 million e-mails.
Experts say the attack was coordinated and used a computer programme that was created specifically for an attack on 33 groups which voiced opposition to Japan restarting its nuclear reactors.
The attack was launched on September 18 and continued until November 4, using a tailored programme to tell the groups' websites it had a request for information. In response, the website sends an automatic reply, but the system was overwhelmed when the programme sent several hundred identical messages every minute.
The denial-of-service attack was followed up by more automatic mails sent to websites, one of which read: "Unless we kill all of the anti-nuclear believers, world peace will never be achieved."
Analysts have been unable to trace the source of the attack as the perpetrator made use of an anonymity system.
"It began with us just receiving hundreds and hundreds of e-mails and it worried us for a while," said Aileen Mioko-Smith, of Kyoto-based Green Action Japan .
