However, Budde questioned the Government's openness on the controversial issue and labelled the whole process "unacceptable" for a democratic society. The analyst also shrugged off the possibility Optus' involvement changes the balance of the game to give the Federal Government's plans more legitimacy.

"'Obviously, from that point of view, Conroy immediately sent out a press release," he said. "But Optus is not going to vote for the Government. The people that are affected by it will vote for or against. In the end that is what counts and I am pretty sure the Minister is well aware of the implications. He is well aware he is not popular with this. I can't see that Optus' participation, therefore, gives more credibility to the project. It might give a little more credibility to Conroy but not to the project."

Optus joins seven other ISPs in participating in the filtering - Primus Telecommunications, Highway 1, Nelson Bay Online, Netforce, OMNIconnect, TECH 2U and Webshield.

The Government release states that for the purposes of the pilot, Optus will filter the Australian Communications and Media Authority's (ACMA) existing blacklist of prohibited and potentially prohibited content for a selection of its customers who volunteer to participate.