The Government's mandatory internet censorship plan, which is already being trialled by a number of small ISPs, will block sites contained on the ACMA blacklist for all Australians. "We are not able to reconcile participation in the trial with our corporate social responsibility, our customer service objectives and our public position on censorship," iiNet managing director Michael Malone said.

"It became increasingly clear that the trial was not simply about restricting child pornography or other such illegal material, but a much wider range of issues including what the Government simply describes as 'unwanted material' without an explanation of what that includes." Betty Peters, 78, a retired nurse educator from Melbourne whose pro-euthanasia YouTube videos were included on the blacklist, said she was "outraged" at the Government's big brother attitude to Australian senior citizens. "We do not need a 40-year-old senator like [Communications Minister] Stephen Conroy deciding for us what is good and bad. I am appalled that our free country has come to this," said Peters, who does volunteer work for euthanasia organisation Exit International.

Senator Conroy and ACMA initially tried to discredit Wikileaks by saying the leaked blacklist was about double the size of ACMA's list. However, they admitted that both lists shared "some common URLs". Wikileaks said the disparity was due to the fact that the leaked list was from August last year and contained a number of older URLs that had since been removed by ACMA.

It quickly followed up by leaking a second version of the blacklist, dated March 18 this year, that is approximately the same size as the ACMA list and contains many of the same seemingly innocuous websites. The renegade site also published instructions on how people can verify that the leaked list is legitimate. The list was obtained by Wikileaks from internet filtering software that parents can opt to install on their computers. ACMA provides its list of prohibited sites to these software developers for inclusion in their products. Wikileaks was offline over the weekend and continues to be inaccessible, with a message on the site saying that it is "currently overloaded by readers". It plans to deploy additional resources to resolve the issue and is calling for people to help out with donations.

Last week's leak of the ACMA blacklist reignited concerns that the internet filtering proposal could have unintended consequences for innocent businesses. Experts warned that Australian businesses could be added to the list in error, with little recourse. They would then be associated with child porn peddlers and sexual violence sites.

"Any person or corporation that would be identifiable on the list would potentially be deemed by the general public ... either a child molester or at least in the same category as child molesters," said University of Sydney associate professor Bjorn Landfeldt. "In effect, this could be interpreted by some as a government sanctioned hate list."