Sounds like they need to call for8 Oct 2013 14:46
“GitHub wipes hand across bloodied face, stumbles from brutal DDoS beating”
Ashley Stephenson, chief exec of security appliance firm Corero Network Security, added the multi-phase pattern of the attack against GitHub is typical of other denial-of-service attacks.
"From what GitHub have disclosed it looks like the DDoS [distributed denial of service] attacks targeted at their networks followed a very typical progression," Stephenson said. "It is not unusual for attackers to probe a site with different attack vectors to figure out what type of vulnerabilities exist. It is likely that as the attacker(s) saw that GitHub were able to stop one type of DDoS attack they modified the characteristics of the attack until the website and services were again impacted."
"A second wave of attacks, just a day later, is also a common sequence, more than likely coming from the same source, having already analysed how GitHub would likely react in trying to mitigate the attack, the second wave of DDoS attacks do appear to have been successful in taking down the site," he added.
http://www.corero.com/en/company/news_and_events/media_coverage?item_id=834