When David Cameron announced that he was planning to force all the ISPs to implement automatic filtering of porn on the internet, a lot of people said it was a good idea in principal. And a lot of people who know how the internet and/or filtering tech works said it’s never going to work.

Let me clear something up. I don’t think kids should be looking at porn. I also don’t think there’s a damn thing (on a technical level) that can be done to stop them.

Filters generally work with blacklists and whitelists, and heuristic patterns. Basically speaking, some sites may never be blocked, others will always be blocked, and the heuristics will likely work with keyword lists, so if a page contains a word like XXX or a phrase like “hot hard-core action”, the filter will probably block that site.

Enter the problem: now this site contains those phrases and isn’t one of the huge well-known sites, it could be blocked by those heuristics. Other sites like LGBT sites, rape support sites, and even teen puberty help sites could find themselves blocked, and not all porn sites will contain those phrases so some will inevitably slip through. What’s more, ISPs could find themselves breaking the law by following the law. The LibDem LGBT site was one of those caught in the crossfire, and blocking the website of a political party around election time could be seen as something like electoral fraud.

Apparently parents can override these filters, but what’s to say that parents don’t let their more knowledgeable kids manage the net connection? Or maybe don’t want to disable them because they’re oblivious to the issues? Or even worse, what if the kid is trying to get support regarding parental sexual abuse?

There is so much that could go (and has gone wrong already) with this, and there’s so much damage that could be done to vulnerable people who are trying to get support. It’s a real kick in the teeth for charitable organisations who are doing their best to help people, and then the government comes along and pushes this through.

This is one of many examples of why I feel so strongly against Governmental intervention in technical matters such as internet governance. If you don’t understand the technology, don’t try and legislate for it. Learn the technology, how it works on a basic level, for example with filtering learn how filtering works, and what sort of things get filtered, advantages and disadvantages, and problems. Don’t assume the industry will work out the problems Mr Cameron.