Pro-WikiLeaks hackers have said that they are launching a cyber-attack on this afternoon because of the etailer’s refusal to host the whistleblower website on its servers.

The group of hackers, called Anonymous, has already attacked payments organisations MasterCard and Visa after they refused to process donations to WikiLeaks.

Anonymous announced on Twitter that it would target Amazon starting at 4 o’clock. There is no sign so far of any disruption on Amazon’s site.

So far the hackers have deployed denial of service (DDOS) attacks, using other people’s computers to increase the traffic load on the target site. High levels of traffic can crash a website.