A security researcher discovered an Out-of-band resource load flaw in Googles servers that allowed him to perform a DDoS attack on remote hosts. Luka Sikic from Croatia was able to gain over 700 Mbps traffic after 10,000 requests. Google has a caching system which is there to prevent this type of issue. Sikic bypassed that security measure and let server think that every request is unique. As a mitigation measure, there should be a better caching mechanism and a detecting system which would not allow unlimited number of requests to a remote host.”]
Source: http://securityaffairs.co/wordpress/56618/hacking/google-ddos.html