Users of the popular Tumblr website launched a preemptive DDoS attack that downed competitor 4chan after rumors circulated that 4chan was preparing to flood rival Tumblr with submissions designed to knock its servers offline.
And so the DDoS war has begun.
4chan users are being encouraged to submit unsavory material to Tumblr, including pornography and gory images, in an effort to overwhelm their traffic capacity and temporarily disable website operations.
Tumblr users had threatened to retaliate by flooding 4chan with images of kittens in what is aptly being called "Operation Overkitten".
DDoS attacks are usually accomplished by utilizing multiple systems controlled through the use of a botnet to replicate the effects seen when a website receives more traffic in a period of time than it is capable of handling, as any daily user of Twitter is quite familiar with.
But the tactical use of coordinated flooding of websites for competitive reasons is unprecedented, and the very public nature of the attacks could most certainly lead to legal actions for interference with business activities.
Scarier yet is the thought that websites with legions of loyal users could be summoned at will to knock websites offline on nothing more than a whim.
Source: http://www.itproportal.com/2010/11/15/4chan-downed-tumblr-ddos-attack-more-threatened/