Pay Centrelink for customised demographic information?

I am doing some research into Centrelink for a Knowledge Management assignment and I came across this tidbit of information on the Port Phillip Website.

Pensions and Benefits Recipients - Centrelink 'Data Shop'

Centrelink provides aged and disability payments, family payments, New Start for unemployed people, Youth Allowance for students and rent assistance payments. Customised data by age, sex, postcode and type of payment is available through Centrelink by emailing specific requests to their 'Data shop'. A fee is charged for this information.
Email. data.shop@centrelink.gov.au

Ahem. Is there not some kind of privacy protection on this information? How specific to what region or population is the information provided from Centrelink? Is there not some kind of ruckus every Census about privacy of information to do with income and small populations? How can Centrelink be providing this kind of information? Are they discerning as to who they tell, or is it fee paid, and no one cares? I might email and ask.