The latest results from the Office of the Australian Information Commissioner's longitudinal study of attitudes to privacy have found that Australians are increasingly worried about the risks.
Almost half believe that online services pose the greatest privacy risk, while fewer than one in 10 think social media websites are trustworthy when it comes to protecting users' privacy.
The other big risks that people are worried about are ID fraud and theft, data security, and the risks to financial data in general.
A majority of people believe that most or all websites and smartphone apps collect user information, and are uncomfortable with that practice.
Yet, half don't read online privacy policies, while less than one third of people habitually falsify their name or details to protect themselves.
Commissioner John McMillan said there has been significant change over the past five years in how people communicate online.
Attitudes to the importance of personal privacy protection have changed at the same time, he said.
A third of those surveyed have problems with the way their personal information was handled sometime during the past year.
Privacy Commissioner Timothy Pilgrim said the survey results make it clear that the Australian public is insisting their personal information be handled with the highest possible privacy standards.
He pointed to the finding that three in five Australians have decided not to deal with an organisation because of privacy concerns.
This is up from two in five, when the survey was last conducted in 2007.
"There is a business imperative for organisations to be transparent about their personal information handling practices and to ensure that privacy is built in to systems and processes right from the beginning," he said in a statement.
Organisations cannot afford to relax when it comes to proper data security, he said.
The survey found that the most trusted institutions for data privacy are health service providers, financial institutions, and the government.
The results from the survey of 1,000 people will be published online.