This December 9, 2010 photo shows the internet site of Amazon.com. After taking down the websites of Visa, Mastercard and others, supporters of WikiLeaks threatened Thursday to knock Amazon.com offline. 'Anonymous,' the loose-knit group of hackers behind the cyber attacks, announced an assault on the Amazon website for 11:00 am (1600 GMT) as part of what they are calling 'Operation Payback.' AFP PHOTO/Karen BLEIER (Photo credit should read KAREN BLEIER/AFP/Getty Images)