The minister must start listening to the experts, who have repeatedly made the point that most predatory risks to children lurk in those areas of the online world this kind of filtering will do little to combat. Technical advice suggests chat rooms, email and peer-to-peer networks are the most dangerous. Law enforcement agencies around the world have revealed that pedophiles use peer-to-peer networks to exchange explicit videos and images outside the world wide web. Experts have also shown how the techno-savvy can use various techniques - including encryption - to bypass filters, leaving web sites you would expect to be blocked, open for all to see.

The most powerful and effective weapon against illegal behaviour online is the same as that for illegal behaviour in the real world: sophisticated law enforcement. The successful operation against a child pornography network by the Australian Federal Police late last year, which resulted in more than 20 arrests, demonstrates that. This crucial capability must not be neglected in favour of an unproven filtering concept experts say will be easy to get around, will not block some offensive content while blocking some acceptable sites, and will slow down the internet for everyone in the process. Wouldn't the $40 million earmarked for the compulsory filtering policy be better spent on funding and resources for law enforcement, to better equip agencies to strike at the heart of child pornography production and distribution?

There are other, more practical filtering options for individual computers, which allow choice, but this government doesn't appear to want that. Labor has closed the program established by the former Coalition government, which provided free, PC-based filters to all families. These filters allowed families to complement their online safety arrangements with software tailored to their individual needs, without compromising overall internet performance. Senator Conroy says too few people used the program. But take-up is driven by demand, and while some parents choose to use a content filter, others, for their own reasons, don't. I installed a content filter on our family's computer and believe it is a worthwhile additional safeguard to help protect my children from being exposed to explicit content.

You would think the take-up rate of the free filter program would tell the Government something about where internet filtering lies in terms of priority to families, but apparently not. If anything, the minister seems to be using it to somehow justify Labor's heavy-handed "big brother" approach. As the debate about Labor's controversial policy has raged, Senator Conroy has remained cryptic and vague, raising suspicion by talking about filtering not just illegal material, but also "unwanted" content that he refuses to specify. He has also resorted to unedifying inferences against those who dared question his plan. When a Greens Senator, Scott Ludlam, asked some perfectly reasonable questions during a senate estimates hearing last October, Senator Conroy responded: "I trust you are not suggesting that people should have access to child pornography."

Newspapers have reported that the minister's office tried to silence industry figures who had publicly spoken out against content filtering. Last month Senator Conroy finally released a damning expert report on ISP-level filtering, which he had sat on since February. Meanwhile, we wait for filtering trials to start, trials that have been delayed and which have next-to-no support among the industry. Telstra BigPond - Australia's largest ISP - has refused to take part, comparing internet filtering to "like trying to boil the ocean". The third largest, iiNet, is prepared to participate to highlight flaws.

No decent Australian would argue against the broad aim of making the online world as safe as possible. But Labor's fixation with compulsory, centralised filtering - which tells parents they are incapable of protecting their children - is not the answer. Nick Minchin is the shadow minister for broadband, communications and the digital economy.