The Code of Practice that forces Internet Service Providers to filter information available on the Web, is little more than "Government endorsed privatised censorship" according Electronic Frontiers Australia (EFA).

It's not the first time the EFA has slammed censorship, but in this instance it is the EFA itself that has been censored - the group's Web site has been blocked by SurfWatch -- a product intended to shelter children from pornography.

SurfWatch is one of the 16 filter providers the government endorsed when its Approved Code of Practice for Internet Service Providers came into effect in January. The products were assessed by the CSIRO for such things as ease of installation and ease of use.

"Nobody's checked that they [the filter provider] actually do what they are supposed to do," EFA Executive Director, Irene Graham told ZDNet Australia.

"We're concerned that because these filters are 'approved', people are being given the idea -- effectively by the Government -- that they can just install these products on their computer and their kids will be safe. Most of them don't even block everything they're supposed to block in the first place," Graham stressed.

According to the Code, any addition or removal of a filter product from the list of 16 will only be done following the approval of the Australian Broadcasting Authority (ABA) and the Internet Industry Association (IIA).

"If the IIA and the ABA are going to state that these filters are approved they need to either have proper third party investigations done on them or the Code should link to various third party reports on the product to give a balanced view," Graham said.

SurfWatch spiders the Web -- much like a search engine -- carrying out text-based analysis -- often for sexually explicit words. If a string of sexually explicit words are found in a document then the product checks links from that site to other sites and does text-based analysis on those links as well.

A SurfWatch spokesperson told ZDNet Australia that an international team of surfers "lays human eyes on every single page to determine which category of filtered material the site should go into". Core categories include sexually explicit, hate speech, drugs and alcohol, violence and weapons.

"The percentage of mis-categorised sites on our list is small to non existent," the spokesperson stressed.

Peacefire -- an organisation which supports free speech for Internet users under 18, and a critic of blocking software, told ZDNet Australia: "From SurfWatch's point of view it may have been an honest mistake."

Peacefire's Web master Bennett Haselton explained that SurfWatch actually blocks a site by its IP address, rather than its individual Web address. As many sites share IP addresses, innocent sites will be blocked alongside the sites SurfWatch intends to block.

"From a programming point of view it is a lot harder to implement the blocking of sites through a host name," Bennett said. " However, it is definitely not true that SurfWatch reviews every site they block," Haselton added.

An ABA spokesperson told ZDNet Australia "we do not endorse filter products".

If a filter were to be removed from the Code, "The initiative would have to come from them [the IIA]. It's their code." "We're aware these products are not infallible," the spokesperson added.

"I'm not aware that they [IIA] have contacted us about SurfWatch, so I don't think there's any action that's pending on them, but Peter Coroneos (executive director, IIA) may be able to throw more light on that," the spokesperson added.

Asked if the list of filters had been modified since in the six months the Code has been operational, the ABA spokesperson said: "I'm not aware of what changes, if any, have been made to that list."

Peter Coroneos was unavailable for this article

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