This paper investigates issues surrounding the Australian governments proposed Internet 'filter' (censorship regime), to be based on existing 'Refused Classification' prohibitions relating to other media such as film and video or publications. Tile planned legislation has focused debate on government Intervention in relation to the risks and dangers posed by the Internet, rather than on the responsibilities and opportunities for both cultural and economic growth via online networks, where potentially every user is a producer as well as a consumer. The paper goes on to analyse the history of censorship classification systems, showing how some aspects-such as the notion of a “reasonable adult” – survive over decades without regard for cultural change, while others are quietly dropped when they become embarrassing. The paper concludes that, since cultural norms change over time and differ from one nation to the next, and that since they evolve as a result of disagreement and debate, the best policy for government is not to ‘protect’ citizens as if they’re all vulnerable and uniformed children, but to protect the spirit of Karl Popper’s ‘open society’, where people learn to be independent and to choose for themselves; a prospect that seems as alien to the minister responsible for the legislation, Senator Conroy, as it appeared distant to Popper in 1945.