As many as four out of five Facebook users accept that the site offers no privacy, unlike the majority of the general population who consider it a private space.

A Privacy Commission survey issued today found 57 per cent of New Zealanders believed social networking sites were mostly private spaces.

But users of social networking sites themselves - a minority at 45 per cent, according to the study - thought otherwise.

Comments left on Facebook to the Herald story were far more cynical.

"Internet and privacy? yeah right," wrote Denby NZ.

"PRIVACY???...... lmao (laughing my a** off)," said Weston Lowe.

"I think ppl who scream privacy hav (sic) dirty secrets and millions to hide under their bed," said Winnie Wong. "Get over it."

Facebook users who did not think they could protect their privacy outnumbered those who thought they could by four to one - and only one of them thought it was a bad thing.

Many assumed the attitude of "who cares if u have nothing 2 hide", as Iron Head Pitz said.

Others said users simply needed to be aware that whatever they posted was public and to be careful.

Also discussed was how to control children on sites like Facebook.

"Im on these sites also so I am on constant watch as to what my teen puts up on her page," said Vicki Svebakk.

Amanda Lio responded by saying a teenager could easily circumvent parents' monitoring. "LOL (laughing out loud) @ the parent who said they're connected to their children's facebook page and monitors everything their children do over the internet," she said.

"No matter how much you want to be in control over your children's internet behaviours, it isn't possible."

Privacy Commissioner Marie Shroff told the Herald yesterday that for many people there was an illusion of privacy on sites such as Facebook.

Ms Shroff encouraged vigilance to protect children on the internet.

"The internet offers a huge amount in terms of entertainment, education and ability to communicate with others, but there are risks too," she said.

"When children are online they can and do give away a lot of information about themselves, without necessarily being aware of the consequences."