The incident started when spam-fighting group Spamhaus added CyberBunker, a Dutch-based hosting firm that will represent anything at all save child porn and “anything related to terrorism”, to a blacklist used by email providers to weed out spam.

CyberBunker retaliated with a huge “denial of service attack”, which basically entails overloading a server with coordinated requests to make it unavailable to its intended users. At one point, a network of computers were sending 300 billion bits per second, making it the biggest attack ever of this kind. Netflix and other major website were effected.

“The size of the attack hurt some very large networks and internet exchange points such as the London Internet Exchange,” John Reid, a spokesman for Spamhaus, said in an e-mailed response to questions by Bloomberg News. “It could be thousands, it could be millions. Due to our global infrastructure, the attackers target places all over the world.”

CyberBunker has denied that it ever sends spam, and has criticised Spamhaus for acting as a guardian over the internet. Sven Olaf Kamphuis, an internet activist who acts as a spokesman for the group, told the New York times:

“Nobody ever deputized Spamhaus to determine what goes and does not go on the Internet,” he claimed. “They worked themselves into that position by pretending to fight spam.”

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