Mr Kalisch believes the attempts to hobble the data collection were malicious. But some cybersecurity and data retention experts say problems may have been caused simply by too many people trying to access the site at once.

Leaving aside the actual cause, in the lead up to census night the ABS had left too many things unexplained for such an ambitious project. Only in the last few days did official sources step up their message that the public had more than one night to complete the census form. They had days to finish it.

Given the window of opportunity, why not break up the task of national data collection with a state-by-state approach, thereby limiting the fallout if something goes wrong?

Last year the ABS said it had spent more than a year developing the means of producing accurate population information without a census and had reached a point where it believed it could accurately update state populations every three months and smaller populations every year.

In February, 2015, the bureau even proposed removing altogether the requirement to a census every five years and replace it with a survey once every 10 years, as happens in Britain and the United States.

Tuesday night's Australia-wide log-on was risky. The Australian Centre for Cyber Security at the University of NSW, Canberra, released a discussion paper in May, which noted the substantial spending gap between what the Australian Government proposes spending on cyber security compared to what its allies are spending.

The discussion paper traces the differences in Australia's assessments of threat in cyber space and the threat assessments of our allies. The United Kingdom released a major policy statement reiterating its view that the cyber menace is a top order national security and economic threat.

The UK paper promised much closer attention than Australian policy has so far to systemic threats to critical cyber infrastructure. Professor Greg Austin, a co-author of the discussion paper, believes many Australians do not see cyber threats in the same way as their peers in our closely allied countries.

As cracks widened in the public's confidence of census night, Shadow Assistant Treasurer and former economist Andrew Leigh appeared more comfortable explaining the importance of participation than the Minister responsible for the census, Michael McCormack, who has been in the job about two weeks.

Unlike other politicians who said they would not be putting their name to the document for privacy reasons, Mr Leigh, while critical of the Minister, was prepared to get behind the process, resisting an opening to turn the heat up even more on a floundering political opponent. It was only after Tuesday night Mr Leigh called it a debacle.

Not so generous in 2014 was then treasurer Joe Hockey who hammered the ABS over the dependability and credibility of its monthly employment figures. The Community and Public Sector Union blamed the government for the inaccuracies, pointing to cuts of $68 million in that financial year and 350 bureau job losses over the past two years.

Restoring confidence in the once-reliable ABS could cost more than what has been saved in recent years.