What is "mafiaboy"

Michael Calce (born 1986, also known as MafiaBoy) is a high school student from West Island, Quebec, who launched a series of highly publicized denial-of-service attacks in February 2000 against large commercial websites, including Yahoo!, Fifa.com, Amazon.com, Dell, Inc., E*TRADE, eBay, and CNN. He also launched a series of failed simultaneous attacks against 9 of the 13 root name servers.