One small piece of mail is causing a big uproar.
New Zealand Post's lifestyle survey has been raising concerns about privacy because some respondents might not know where the information gathered is going.
The survey is being delivered to households throughout the country and asks recipients to respond to questions to be in for a chance to win prizes.
Questions range from finding out people's favourite supermarkets to what they do in their leisure time.
The data collected can then be rented by New Zealand Post to companies who wish to access the information.
The issue's been raised with Mangere MP Su'a William Sio who says he wants south Aucklanders to know they don't have to fill out the survey.
Mangere Bridge resident Duncan Stone believes some people don't expect NZ Post to engage in activities he calls an "invasion of privacy".
"If you want your mail to come through you have to supply your name and address to the post office and they're using that information to make this offer to you."
Mr Stone says the prizes are a way of drawing people in without understanding what they are getting themselves into.
"The implications of this won't dawn on a lot of people," Mr Stone says.
"Most people will find it quite attractive."
After having spent most of his life around numbers as an accountant, the 82-year-old says the prospects of winning are "pretty jolly remote".
Mr Sio says he shares the concerns of many of those who've raised the issue with him.
"I do not like my personal information being sold off to commercial interests so that they in return target me with their advertising or – if sold off to unscrupulous operators – target our community with scams," Mr Sio says.
NZ Post was criticised after its 2009 survey and has made changes to this year's, its communications manager John Tulloch says.
Two reports carried out for Privacy Commissioner Marie Shroff said the company's 2009 survey, distributed to 800,000 letterboxes and via email, breached privacy principles and was unfair in terms of marketing industry standards.
Mr Tulloch says it's clear the survey is optional and he's quick to point out the word voluntary appears 11 times.
"We're a state-owned enterprise, we're not a government department, we're not a ministry, we're a business and this is a perfectly valid business activity."
People are more vulnerable to data-mining on Facebook when they use applications and play games, Mr Tulloch says.
And the company has numerous safeguards in place and is very cautious who it gives information to, he says.
Respondents don't have to fill in all the questions and if they want to they can request their name is removed from the database at any point.
Massey University head of communications, journalism and marketing Malcolm Wright says while NZ Post might be within its legal rights to call the exercise a survey, it breached the Market Research Society of New Zealand's voluntary code of practice.
"They shouldn't call it a survey, they should call it an opportunity to join a direct mail database," Professor Wright says.
- Manukau Courier
Are our classrooms becoming overcrowded?