We won't see mandatory Internet filtering until mid-2010, but even without the details still being worked out, it's clear that anyone with a modicum of technical know-how will be able to bypass it.
At tech opnion blog Hydrapinion, Anthony Caruana highlights two obvious ways that people concerned that their access to legitimate material is being blocked can access it:
Simply Google for something that's on the blacklist and rather than opening the link to the search result click the "Cached" link. This will direct you to a copy of the content that's stored on Google's servers as part of their index. Somehow, I doubt that the Australian government is going to block Google. Alternately, you can sign up for one of the hundreds of free or cheap VPN services that are available.
Of course, if you use those techniques to access content that's outright illegal, you shouldn't be surprised if the police come knocking. But given the high likelihood that content will get misclassified, either through human error or deliberate political attempts to block what's seen as undesirable material, these kinds of tactics are bound to become more common.
Bypassing Australia's Net Filter [Hydrapinion]