The NSW government has committed to a review of defamation laws after a top defamation judge called for an urgent and comprehensive overhaul to reflect the rise of social media cases and the challenges posed by online publications.

Judge Judith Gibson, who runs the defamation list in the NSW District Court, said two-thirds of cases now involved the internet and existing defamation laws were "out of sync" with technology. The failure of successive governments to review the laws was "unacceptable", she said.

NSW District Court Judge Judith Gibson says "much of the law reform debate in Australia is still stuck in a pre-technology loop". Credit:Peter Rae

Judge Gibson said Rebel Wilson-style defamation cases involving "typical tabloid excess" and large media companies were now the exception and "increasingly what we're seeing is attacks on people on social media" by private citizens.

Those cases posed a range of difficulties for existing defamation laws, including that available remedies were often ineffective when defendants were "anonymous ... or penniless".