New Zealanders have been reminded that their personal information is the price they pay to use social networking sites as a survey shows nearly 9 out of 10 youngsters use Facebook.
The UMR privacy survey, released today, shows social networking use has soared from 14 per cent of the population in 2007 using Facebook to 54 per cent this year.
But despite an apparent addiction to social networking, New Zealanders say they are concerned about what happens to the private information they put on the network.
Seventy-four per cent have changed their Facebook privacy settings at some stage, up from 66 per cent last year.
Privacy Commissioner Marie Shroff said that change in behaviour sent a message to internet corporations about people's expectations of privacy.
"The digital revolution is driving concerns among New Zealanders," Ms Shroff said.
"The survey shows that people are increasingly conscious of privacy while they're engaging online, so there are some lessons in here particularly for the internet corporate giants."
Ms Shroff said the 55 per cent of New Zealanders who Facebook is a "private space" were naive.
"Facebook itself, and sometimes its business partners, may be able to use the information you put up there for their own needs.
"There's no such thing as a free lunch - our information is the product that the internet giants are using. So it is slightly risky to assume a social media site is private."
More than three-fifths of respondents said they were uncomfortable with Facebook and Google keeping information on what they have said or done online.
Last year, Facebook's tracking technology landed the social networker in hot water after an Australian blogger published data showing it gathered information on the online activities of users.
In response, Facebook promised to fix a "bug" which meant logged-out users could be identified as they visited many other sites on the web.
Netsafe's chief technology officer, Sean Lyons, said even the amount of information people voluntarily gave Facebook meant targeted marketing would occur.
"If you think about the amount of information that Facebook has - I like this, I've been here, I've travelled to this place, these are my friends - there's an awful lot of information right there.
"We use a product like Facebook that we don't pay for ... it makes its money from advertising, from sharing with other people the information that you chose to share with it."