There is currently an ongoing distributed, denial of service (DDOS) attack underway on the popular website github.com.
(https://github.com)
The attack appears to be designed to punish Github for hosting materials that the Chinese government does not want their citizens to be able to access. You can read more about the attack here:
http://insight-labs.org/?p=1682
https://status.github.com/messages
http://www.theverge.com/2015/3/27/8299555/github-china-ddos-censorship-g...
Github is a website used by businesses of all sizes all over the world - this action (seemingly by the Chinese government) greatly impacts those businesses, as well as Github itself.