Vocus/NextGen caused Census outage, page-4

Actually, you can view DDOS attacks from sources external to Australia through various websites. A security architect I worked with determined that there was no external attack. In actual fact, NextGen offered DDOS prevention services and IBM declined it.

To verify, you can actually check it here:
http://www.digitalattackmap.com/


(There was an attack on the 8th which lasted until 1:28AM GMT (or 11:28AM Melbourne time) - before people started using the Census website)

IBM are in fact, lying. Geoblocking would have done nothing in this case - they should have implemented a form of DDOS protection.