SYDNEY • A backlash against Australia's national census is gathering momentum as lawmakers joined calls to boycott yesterday's population count because of concerns that data gathered will be used to build wide-ranging profiles of individuals and violate their right to privacy.

Senator Nick Xenophon, who leads a minority party in the Upper House of Parliament, said he would refuse to provide his name to the compulsory census and thus would not be able to submit a completed document, risking a fine of A$180 (S$185) a day.

At least six other senators, including five from the Greens party, have followed suit and threatened to withhold their names.

Fearing a widespread boycott that could compromise data that's essential for public service provision, the government has sought to downplay the concerns.

"I note, with some humour really, that many people are going on Twitter and Facebook and making various comments about the ABS, about the census, and about me as well, when in fact wherever they go, it tracks you, on your Facebook account," said Mr Michael McCormack, the minister responsible for the census, ABC News reported.

"So I can't really see what the big deal is; I think sometimes it's much ado about nothing, really."

"Privacy matters," Mr Xenophon said, adding that the Australian Bureau of Statistics (ABS) "has failed to make a compelling case on why names must be provided and stored for four years".

"All names will be turned into a code that ultimately can be used to identify you," he added.

The crux of the debate is over a "statistical linkage key" that will be created for an individual from the name submitted on the census form. Names will also be kept for four years rather than being destroyed after 18 months, as is the current practice.

Privacy advocates say that, irrespective of names being destroyed, the linkage keys will allow answers to future questions to be linked to census responses, enabling the government to compile a profile of a person.

If people boycott the census, or provide incorrect information, the five-yearly questionnaire may not provide an accurate snapshot of the nation. The census data is used to benchmark the population for figures like unemployment and determining the amount and location of public services required.

The public's reluctance about the government holding more personal data reflects concerns about its overall security, said Dr Zareh Ghazarian, a lecturer at Monash University's School of Social Sciences.

"Recent stories of hacking and other breaches of security where people's details are leaking out are feeding into a more refined sense of the dangers of data collection and data retention among Australians," Dr Ghazarian said.

"Major leaks and the advent of groups like WikiLeaks have really made people aware that the data they give to the government or other parties may at some point be released into the public sphere. This census, and the fact it's being conducted online, just reinforces those concerns."

Mr Xenophon plans to contest any fine and turn it into a test case on the validity of the statistics bureau's request. He will also seek to amend legislation so people cannot be prosecuted for refusing to provide their name.

The ABS expected two-thirds of people to submit an online census form by last night's deadline, each requiring an individual code previously sent in the post. The remainder of respondents are expected to use paper forms which could be requested from ABS.

BLOOMBERG