After taking down the websites of Visa, Mastercard and others with Cyber Attacks supporters of WikiLeaks tried but failed on Thursday to knock online retail giant Amazon.com offline.
The loose-knit group of hackers known as "Anonymous" announced an assault on the Amazon website for 11:00 am (1600 GMT) as part of what they are calling "Operation Payback".
The Amazon.com website did not appear to have experienced any downtime, however, and Anonymous acknowledged defeat on another Twitter feed used by the group to coordinate operations.
In a typical DDoS attack, a large number of computers are commanded to simultaneously visit a website, overwhelming its servers, slowing service or knocking it offline completely.
Amazon last week booted WikiLeaks off its servers, saying the company had violated its terms of service, and PayPal has stopped accepting donations for the website behind the release of secret US diplomatic cables.
The Anonymous hackers have also targeted the websites of Mastercard and Visa over the past two days for severing ties with WikiLeaks.
While Anonymous has been launching a wave of attacks, the group has also come in for sanctions itself from Twitter and Facebook. Although Facebook and Twitter both have removed the WikiLeakes Page. Twitter has suspended a account naming Op_Payback.