Communications Minister Stephen Conroy has pushed ahead with the controversial national content filtering scheme with a $125.8 million budget allocation announced today.

The plan has provoked a wrath of criticism from industry and privacy groups, who previously attacked the scheme when it was announced in January.

Conroy said ISP content filtering will be part of a wider plan to fight child pornography, including $49 million to aid Australian Federal Police law enforcement.

"The Internet has exposed [children] to continually emerging and evolving dangers that did not previously exist," Conroy said.

"While there may be technical and cost hurdles [for content filtering], the message from other countries is that these can be overcome.

"Cyber-safety means helping parents and teachers as well as educating children to be good cyber-citizens."

Electronic Frontiers Association chair Dale Clapperton said the government should do more research into the feasibility of content filtering before allocating funds.

"We are disappointed that the appropriation of money seems to prejudge the question of whether it is feasible to implement content filtering," Clapperton said.

"We need more details on what the government is actually proposing to do so we can engage in informed dialog."

NSW Council of Civil Liberties president Cameron Murphy said the scheme is a token gesture and will do more damage to freedoms than restrict child pornography.

"This is the way China goes about stopping its people reading illicit material and by substance of the proposal, Senator Conroy is the same," Murphy said.

"Parents need to take more responsibility for what their children view.

"There is no proper classification process for this kind of content blocking. The technology is not up to it, whether it is linguistic-based or Web site-based."

The opt-out plan requires all ISPs to filter "objectionable material" from Internet traffic according to a blacklist defined by the Australian Communications and Media Authority (ACMA).