PARENTS should not stalk their children online, warns Dr Danah Boyd, a leading US cyber safety expert visiting Australia to lecture on teens' online privacy.

Described by The New York Times last month as ''a rock star emissary from the online and offline world of teenagers'', the 34-year-old New York University professor and Harvard researcher advises governments, corporations and organisations worldwide on teen communication. She is leading Microsoft's investigation of child trafficking online, and Lady Gaga funds her bullying research through the Born This Way Foundation.

Dr Danah Boyd.

But Dr Boyd warns that constant parental online surveillance not only abuses teens' privacy but also obliges them to forge coded forms of communication online, using in-jokes, shared references and even song lyrics to evade parental scrutiny.

''The kind of public life we see online has never existed before,'' Dr Boyd told Fairfax Media ahead of her lecture at RMIT on Thursday. ''But it's a myth that teens don't care about privacy. It's really impressive what teens do to find new ways to be private in public.''