Free speech means accepting that stuff will be said that you disagree with, but there's plenty of people who spend their lives complaining about viewpoints or media they don't like. What will those people start doing when Internet content can be blocked via a mandatory censorship scheme?
Censorship blog Somebody Think Of The Children has rounded up a list of Australia's biggest cases of moral panic for 2009. It's a noteworthy list because it demonstrates how hard it is to come up with well-defined community standards that everyone can agree on, and how inconsistently judgements tend to be made about those issues.
It's very hard to believe that the same sort of complaints won't be made about web sites, even if they don't feature content that would be refused classification (the current basis for the government guidelines, but one that's hard to measure as the reasons for banning and indeed the list of banned material won't be made public).
To make your voice heard on this issue, check out our guide to protesting against Internet censorship proposals.