Michael Calce (Mafiaboy)
The fifteen-year-old from Montreal who took down Yahoo, eBay, Amazon and CNN with denial-of-service attacks in February 2000.
Over one week in February 2000, some of the web's biggest sites fell over one after another. Yahoo, then the internet's largest portal, was offline for about an hour; eBay, Amazon, CNN and Dell followed. Behind it was Michael Calce, known as Mafiaboy, who controlled a network of hijacked university machines and bragged about it in chat channels – which is how the FBI and the Royal Canadian Mounted Police found him.
In 2001 he was sentenced to eight months in a youth detention facility. The attacks pushed the US government to treat DDoS as a threat to infrastructure for the first time, turning a teenager's project into a matter of national policy. Calce has since worked as a security consultant and written a book about the episode.