The group, which dubs itself Anonymous, has achieved online notoriety for previous attacks against the Church of Scientology.
The group appears to have detailed public plans online to start attacking the websites, email addresses and fax numbers of the Federal Government, particularly Communications Minister Stephen Conroy and the Australian Communications and Media Authority after the expiry of an ultimatum published one month earlier.
"A state of war between Anonymous and the Australian Government, and between Anonymous and all other governments which find themselves so inclined to impose censorship upon the internet, will be recognised," the site, which describes the proposed attack as "Project Didgeridie" states. "We need to blast their servers into the dust."
Intelligent Business Research Services advisor and security expert James Turner said Anonymous should let Australians deal with the internet filter issue as per normal political processes.
"We are a democracy and this is one of the most popular governments ever," he told ZDNet.com.au this morning. "In contrast to this, the censorship plan has clearly been driven by a few fringe politicians who are out of touch."
"If these politicians fail to understand the sentiment in Australia around this censorship plan then it's very likely that they will be removed from their seats at the next election. This is how Australia works. We're probably the most stable democracy in the world, and we'll simply vote these politicians out."
Turner said Australia's press had done a "sensational job of eviscerating the censorship plan", which he said was "now effectively dead in the water". Consequently, violent attacks were not required.
A spokesperson for Minister Conroy's office had not yet responded to a request for comment on the issue.