Under the Census and Statistics Act it is an offence to release any information collected under the Act that is likely to enable identification of any particular individual or organisation.
For the Census, strict measures are taken in field collection, processing and output of data to guard against the release of confidential information.
Census collectors are responsible for ensuring the Census forms for their Collection Districts are secure at all times. Strict building security is maintained at the Census Data Processing Centre (DPC). After processing of the forms has been completed they are pulped under the supervision of an officer of the ABS. All records used by collectors are destroyed.
Prior to the 2001 Census, all name-identified information was destroyed once the statistical processing was completed. However, for the 2001 Census, respondents were given the choice of having their name-identified information archived for the research use of future generations. For the 2006 Census and future Censuses, respondents will again be given this choice.
The retained name-identified information is not available for any purpose, including use by a court or tribunal, within a 99 year closed access period. Retained name-identified information from the 2006 Census will become publicly available in the year 2105.
To ensure the current high level of cooperation in the Census is maintained, information is only kept for those persons who explicitly give their consent, respecting the wishes of those who do not wish their information to be retained. If a person does not explicitly agree to their name-identified Census information being retained, their name and address will be destroyed once statistical processing has been completed.
Customised tables for some geographic areas can be produced with cells containing very small counts. In cases where this occurs small random adjustments are made to the data to avoid any risk of releasing identifiable information. These adjustments allow for a greater amount of detailed data to be released, and, as they are small, do not affect the utility of the data.
A comprehensive list of the precautions taken to ensure confidentiality of Census data is published in the information paper 2006 Census of Population and Housing: Nature and Content (cat. no. 2008.0).
See also Introduced random error.