There are some concerns about the filter at a technical level. If you want to get your head around those, I recommend you look at the TechLiberty article on Security Risks fo Centralised Filteringor InternetNZ’s positioning paper.

The risk to the function of the internet is relevant to NetSafe, but not central to our interest. We need to know how the filter impacts on the overall safety equation in this country – because we have a responsibility to coordinate the cyber safety community.

ACMA have produced three reports for the Australian Minister for Broadband, Communications, and the Digital Economy around Online Risk and Safety in a Digital Economy. Critical to this discussion is the key finding of the second report – it identifies that “the effectiveness of strategies to mitigate online risk and promote online safety is enhanced when responses to risk are deployed at multiple points along the supply chain for online content and services”.

No surprises there. No single strategy makes a safe environment. Instead, you enhance safety through multiple activities, of which filtering is an option. Like any multi-part strategy, you make gains when you coordinate them properly. 

The DIA is providing a filter which some (maybe all) ISPs will adopt. That changes the safety landscape. It impacts on the other safety and enforcement organisations. We don’t know exactly how, but we should try and find out. 

That starts with identifying what difference a filter will actually make to the trading of child sexual abuse images. I’ve been surprised to find (so far) that nobody really knows. That a web filter negatively impacts on the trade is simply accepted, and little thought appears to have been given to any further analysis. 

What if the filter gives people a false sense of security and they ignore (or de-prioritise) education responsibilities? What if the filter forces deliberate traders to develop new technical skills, and makes them harder to catch? What if the filter is removing (because it doesn’t record) useful intelligence for law enforcement agencies looking for offenders against children in this country?

What if the filter doesn’t actually reduce trading? What if it just changes the way its done? 

That doesn’t necessarily negate the value of the filter – but it does mean the rest of the safety community needs to adjust their practices accordingly.  This is the reason that the NetSafe Group is meeting to discuss the new filter.

This has generated some debate. Before going further – I’d like to note that in this particular case were talking about very specific filtering of one type of image – not general filtering of age inaaproriate content such as that which you can already purchase from some ISPs.

Proponents of filtering will note that accessing child sexual abuse images from New Zealand is an offence under the Films, Videos and Publications ACT 1993 – and a filter merely enforces that law. I recently saw some statistics that estimated 20,000 new images of this type are created each month. Behind each image is a child victim.  Of course, children were victims  of this abuse long before the internet - but the internet has facilitated an evolved business model where images are swapped and sold. Therefore people who view, trade and buy these images online are generating demand for them.

An effective filter would disrupt this trading.  I deliberately use the world ‘disrupt’ because I wouldn’t want to give the impression that filtering can stop it. Many images are traded within peer-to-peer networks which won’t be filtered.

An effective filter would also prevent people from accidently stumbing on this sort of content.  

The opponents of filtering have a number of arguments.

• Filtering adds another step (checking the URL) in the transfer of data on the net which invariably impacts speed. This at a time when we’re looking to increase internet speeds.  
• The filters invariably suffer ’scope creep’. They start out with a narrow focus, but once the technology is in place – other types of content are added. Even assuming that the filter only ever filtered ’illegal content’ - not all ‘illegal’ content is as easy to define as Child sexual abuse imagery.
• The filters can create a false sense of security.

I think the trial is important, and so is public debate about what level of filtering is appropriate for a country like New Zealand.

And I would sign off this post by noting there are other ways to fight this practice such as increasing the capacity of the DIA enforcement team and increasing penalties and/or increasing rehabiliation services  for offenders.