Google and Yahoo could be in for a booting after they criticized Austrialia’s controversial internet filter plans which include a mandatory filter which would block all RC (Refused Classification) content.

Like Bart and Homer before them, Yahoo and Google may be stepping into sticky territory Down Under.

The net giants have put their combined weight behind several Australian organisations – including the Australian Library and Information Association (ALIA) and the Inspire Foundation, which encourages young people to get online – calling for a “rethink” of the idea, according to a report on the BBC.

The groups argue that the subjects covered by RC material are too wide-ranging for a blanket ban. They also warn that the filter will not “effectively protect children”, claiming in this instance that this is because “hardcore material, specifically that featuring children, tends to appear on chat-rooms and peer-to-peer networks which are more difficult to filter.

ALIA’s Executive Director Sue Hutley said that blanket bans on material through filtering have been “shown to trap legitimate information and adversely affect valid internet access and performance”. The statement on the ALIA website adds that a report about government trials of the filter acknowledged the strain of filtering sites with very high traffic. Dealing with sites such as YouTube could “cause additional load on the filtering infrastructure and subsequent performance bottlenecks,” they claim.

The filter, first announced by Stephen Conroy (Australia’s Minister for Broadband, Communications and the Digital Economy) in 2008, has proved controversial. Indeed, late last week an activist group called Anonymous attacked several official Australian government websites in protest, taking them offline for short periods of time. A man claiming to be a representative of the group said that around 500 people were involved in the attack, using a method known as Distributed Denial of Service (DDoS).