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Inside the business model for botnets - MIT Technology Review

Botnets are shadowy networks of computers controlled by hidden actors and linked to everything thats bad on the web. They have been implicated in distributed denial-of-service attacks, spamming campaigns, click fraud, and bank fraud, to name just a few of the nastiest flavors of cybercrime. Clearly somebody, somewhere is making a fortune masterminding this kind of criminal activity.