Many Australians were unable to complete the Census on August 9 due to the Census website failing.

The Australian Bureau of Statistics (ABS) chief statistician has blamed a deliberate ‘denial of service attack’ for the failure.

Like many government information systems, the Census site was outsourced to an external contractor: IBM. As well as writing the software required for the website, IBM was responsible for providing the computers that hosted it.

All of this is routine for IT projects, both government and commercial. While reasonably large, the legitimate traffic generated by the Census is dwarfed by the traffic on websites like Google, Facebook and even the non-profit Wikipedia.