Privacy Commissioner Marie Shroff is warning users of social networking websites to be more security conscious, after a big increase in identity theft and other criminal activities.
Ms Shroff says recent industry reports show there's been a 70% rise in spamming and malicious software, used in the theft of personal details.
She says the growth of social networking will only encourage criminal activity, and people need to think carefully about what personal information they make available online. Vigilance is the best protection, she says.
Netsafe, which promotes safe and responsible use of the internet, recommends the regular changing of passwords and checking security settings.