Millennials don't care about privacy because they share (or overshare) their life on social media, right?

Attorney-General George Brandis certainly thinks so. In the debate around the need for security agencies to access encrypted messages, he said:

"There is an entirely different attitude to privacy among young people than there was perhaps a generation ago."

On a similar note, Facebook founder Mark Zuckerberg once said the "social norm" of privacy was "evolving":

''People have really gotten comfortable not only sharing more information and different kinds, but more openly and with more people. That social norm is just something that has evolved over time."

But it's not actually that simple. A new survey sheds some light on what young Australians really think about online privacy.

Privacy does matter to young people...

The survey of 1,600 people, commissioned by the digital rights and governance group at the University of Sydney, asked a series of questions about privacy in the digital world.

Nearly 40 per cent of respondents disagreed with the statement, "There is no privacy, get over it" — and young people were more likely to disagree.

People over 70 were the most likely to agree that there is no privacy online, and that people should get over it.

Older people were also the most likely age group to say, "I have nothing to hide", with 77 per cent over 60 agreeing with that statement, compared with 56 per cent of those aged 18 to 29.

...but older people are more worried about privacy

When asked whether "Concerns about privacy online are exaggerated", more than half the respondents disagreed and concern was higher among older people than those aged 18 to 29.

However, even in that youngest age group, people were much more likely to dispute the idea that privacy concerns were exaggerated than they were to agree.

Interestingly, across all age groups, up to one-third of people were neutral or undecided — meaning perhaps there remains a degree of indecision or confusion around the issue.

Young people are more in control of their privacy

Younger people felt more in control of their privacy online, perhaps explaining the lower concern among that group.

Half of 18 to 29 year-olds felt they could control their privacy online, compared with around 34 per cent of those aged over 40.

Young people were also more likely to have changed the privacy settings from the default on their social media platforms than older users.

Study author Ariadne Vromen, professor of government and international relations, says it is not surprising young people feel more able to protect their privacy.

And it partly comes down to the platforms they're using.

"There are all sorts of social media platforms that older people aren't using where you can control your privacy much more than on Facebook — things like Snapchat and Instagram but also ones like Tumblr where people are much more anonymous. These are young people's spaces and they have a sense they can control their privacy."

Many worry about corporations and government violating their privacy online

People were most worried about corporations violating their privacy online, followed by government or other individuals but there were few differences between age groups.

The authors noted that what people were most concerned about was not what information was collected or held about them, but four in five respondents wanted to know what corporations would to do with the information.

Eighty per cent of people said it was a breach of privacy for governments to force phone companies to keep metadata on phone calls — something it is already doing.

Around 58 per cent were against governments forcing internet providers to store metadata on internet use (which they are also doing), but that went down to 47 per cent when people were asked whether they favoured police and security agencies being able to access metadata.

When the question was framed in terms of government collecting internet communications as part of anti-terrorism policies, only 31 per cent were against it.