Australia's 2016 census website crashed on census night — IBM paid for the outage

Australia's 9 August 2016 census was the first designed to be filled in online, and the government had heavily promoted it. On census night, after four denial-of-service events, a router failed and the ABS lost its ability to geographically block incoming traffic. Material of unknown provenance was now inside the system, and neither the ABS nor IBM could say what it was. Within hours, Australian Statistician David Kalisch took the entire online form offline 'to protect the system'.

The site stayed down for roughly two days while ABS, IBM and the signals directorate checked whether any data had been touched. Because the census is compulsory, the blackout became a national story within minutes, and public confidence in the security of the data collapsed alongside the website.

The reckoning landed fast. Prime Minister Malcolm Turnbull confirmed IBM had paid the Commonwealth a 'very substantial financial settlement', saying 'overwhelmingly the failure was IBM's, they've acknowledged that'. The government's cyber security adviser Alastair MacGibbon blamed a 'cosy' ABS–IBM relationship that could have bred complacency. The ABS's 2016-17 annual report booked a $24 million budget blow-out — four per cent of its planned expenses — which it attributed directly to the outage.

A$24m ABS budget blow-out in 2016-17 (4% of planned spend); IBM paid a confidential 'very substantial' settlement

IBM's platform survived four DDoS waves, but recovery from one of them dropped the geo-blocking that was the real defence — a single point of failure guarded the whole form.

With unknown traffic inside the system and no tested playbook for 'attack plus equipment failure', the ABS chose the only safe option it had: shut the form and verify.

MacGibbon's review found a 'cosy' long-running ABS–IBM relationship that could have led to complacency on the contractor's part.

The census is compulsory and privacy-sensitive, so a security scare destroyed not just a night of uptime but the trust the entire exercise runs on.

The plan assumed failures come one at a time. When the DDoS shield and a router failed together, nobody could say if data had leaked, so the form was switched off entirely. Rehearse for coincidences.

The Senate Economics References Committee tabled its report, '2016 Census: issues of trust', in November 2016. IBM's settlement with the Commonwealth stayed confidential but, per Turnbull, covered the government's extra costs; he suggested 'heads have rolled' at IBM, though the company's ANZ chief told senators no staff were dismissed over the census. The ABS booked a $24 million blow-out for 2016-17 and spent the following years rebuilding public confidence ahead of the 2021 count.