The “Great Cannon” has entered the cyberwar lexicon alongside the “Great Firewall of China” after a new tool for censorship in the nation was named and described by researchers from the University of Toronto.The first use of the Great Cannon came in late March, when the coding site GitHub was flooded by traffic leaving it intermittently unresponsive for multiple days. The attack, using a method called “distributed denial of service” or DDoS, appeared to be targeting two specific users of the site: the New York Times’ Chinese mirror, and anti-censorship organisation GreatFire.org.
http://www.theguardian.com/technology/2015/apr/13/great-cannon-china-internet-users-weapon-cyberwar