The founder of the world wide web has sounded a warning about the dangers posed by governments intent on increasing the level of monitoring and filtering of the online activity of its citizens.

Sir Tim Berners-Lee said that while it was important to fight serious organised crime and for a state to defend itself against cyber attack, there were enormous negatives associated with excessive government oversight of the internet.

"The whole thing seems to me fraught with massive dangers and I don't think it's a good idea," he said in Sydney on Tuesday in reply to a question about the Australian government's data retention plan.

Sir Tim was speaking at the launch of the CSIRO's $40 million Digital Productivity and Services Flagship, a research facility focused on facilitating the growth of the digital economy and exploiting the full potential of the National Broadband Network.