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.

Filtering filth will not tangle the net by Jim Wallace

It will be the downfall of the internet, the end of free speech as we know it. It will lull parents into a false sense of security, and it doesn't even work.

But just as students are taught not to believe everything they read on the internet, so should we not believe everything said about it. Some things are too important to leave to drown in a pool of misinformation, and internet filtering is one of them.

The industry tries to tell us we don't want this, but a national Newspoll commissioned by the Australia Institute in 2003 showed that 93 per cent of parents of 12- to 17-year-olds said they did. We can assume they would only want it if it worked, and current trials of automatic filtering of pornography are meant to see if it is technically feasible. The results of the two trials to date show that it is increasingly so.

Our dependence on the internet makes us all very sensitive to anything that might degrade its performance, and opponents of filtering have mounted a shamelessly misleading campaign to exploit this fear.

The activist group GetUp!, for example, has raised a petition with the alarmist statement that filtering "will slow the internet by up to 87 per cent", but the claim is based solely on the worst results of the products trialled.

It conveniently omits to advise would-be signatories that the trial results released in mid-2008 showed another of the filter products tested slowed internet performance by less than 2 per cent, and three products slowed it by less than 30 per cent. As one commentator has noted, GetUp!'s selective use of figures is like reporting on the first trial of refrigeration and writing off the technology because one freezer failed to cool the meat.

Another legitimate test for any filtering system is that it doesn't block an unacceptable level of legal material.

Internet service providers and the sex industry would want us to believe it would, and have commissioned at least one study full of expressions of woe. But isn't that why we're having a trial?

The latest Australian Communications and Media Authority trial report, published last year, showed the proportion of illegal and inappropriate content that was successfully blocked averaged above 92 per cent. This was a significant improvement on the 2005 trial, and we would expect more improvements in future.

Just as importantly, the rate of "over-blocking", or preventing access to acceptable material, was in most cases less than 3 per cent, also a dramatic improvement on the 2005 trial. And again, unless you are a technology sceptic, this is inevitably going to improve.

Realising that the trials are likely to prove them wrong, opponents of filtering have thrown in something sure to get everyone animated: "censorship".

From the outset, it has been clear this system is not going to stop any adult from viewing anything that is legal. They can "opt in" to do so. Child pornography would be blocked to all, but the benefit of the initiative is not just in terms of how well it deals with child pornography, but how well it meets the aspirations of the 93 per cent of parents of 12- to 17-year-olds in protecting their children from both legal and illegal pornography.

Contrary to some of the dubious claims, there is a very real problem with children being exposed to inappropriate material on the internet.

In their 2003 report for the Australia Institute, Clive Hamilton and Michael Flood said: "Eighty-four per cent of boys and 60 per cent of girls say they have been exposed accidentally to sex sites on the internet and two in five boys deliberately use the internet to see sexually explicit material, with 4 to 5 per cent doing so frequently …

"There are special concerns regarding violent and extreme material on the internet including depictions of non-consenting sexual acts such as rape and bestiality."

Concerned parents do not view filtering as interfering with their parental responsibilities; they welcome the help. There is no substitute for parental supervision, but parents cannot be everywhere. They expect governments to help provide a protective environment.

The internet is a fabulous resource for everyone, including our young people, but it has the potential to cause great harm if reasonable safeguards are not put in place. The real story here is not the dreadful repercussions of having internet filtering, but the dreadful repercussions of not having it.

Jim Wallace is the managing director of the Australian Christian Lobby.