Today David Cameron is making a speech in which he is widely expected to announce plans to force Internet Service Providers (ISPs) to automatically block access to pornography unless users specifically opt in. In addition, online porn depicting rape will be outlawed in England (it is already illegal in Scotland) and search engines will automatically block what Mr Cameron will call ‘illegal content’, meaning images of sexual abuse of children online.

Nobody disputes the fact that access to online pornography is easy, and unfortunately it’s difficult to stop children accessing the same material – be it by stumbling across is accidentally or being sent it by friends or adults who are looking to do them harm. So the argument to ‘do something’ has been compelling for some time, and the government is determined to be seen to be acting. But is this the right response, and will it work?

The first thing to note is that this isn’t just one response. Mr Cameron is announcing a raft of measures, some of which are to crack down further on images of child abuse online. Others are about children accessing inappropriate content in the home. Others are about adults accessing pornographic content in public places where children could potentially see it. Still others are about adults accessing sexual content in their own homes which may or may not be illegal. And by announcing all of the measures in one go, Mr Cameron risks confusing a number of different issues and applying the wrong solution to the wrong problem.

Start with online child abuse. Anything that the government, search engines, ISPs and parents can do to prevent it happening in the first place is self-evidently positive. Work also needs to be done to tackle the hosting of those images online, and paedophiles accessing them. The Child Exploitation and Online Protection Centre (CEOP) will no doubt be delighted at the expansion of their powers and of the secure national image database for police to use to help track down extreme imagery. Whether search engines will be able to hit the government-imposed October deadline for putting in ‘further measures’ to block illegal content remains unclear.

Then there is ISP-level filtering. From the end of next year, every ISP will be forced to ask each of its users to ‘opt in’ to being able to access adult images. There are a number of problems here: firstly, as the ISPs regularly point out, it’s not a matter of throwing a switch to block porn. Anyone who has done a Google Image Search knows that computers are not as good at recognising images as they are at recognising words, and images can be deliberately ‘tagged’ with misleading descriptions to evade such filters. This sort of blanket block also runs the risk of screening out sites aimed at teenagers which provide advice on physical and mental issues related to growing up. Finally, it’s not clear from the extracts of Mr Cameron’s speech whether the block will just relate to porn or whether other ‘adult’ content such as gambling, or sites containing material pertaining to teen anorexia, will be included.

There is also the plan, first announced earlier this year, to stop children (and adults) accessing (legal) pornography in public places by working with public Wi-Fi providers. This raises still more issues.

There is also the plan, first announced earlier this year, to stop children (and adults) accessing (legal) pornography in public places by working with public Wi-Fi providers. This raises still more issues. There is still nothing to stop an adult watching a pornographic film they have previously downloaded on their device in a public place. And although not many adults may choose to do that, what if an adult wants to watch an 18-certificate film they have downloaded while they are on a plane, and that film contains imagery which children should not see?

Nobody disputes that children need greater protection from the darker side of the internet. But, while it garners family-friendly headlines, today’s speech announces measures which may prove not to be technically possible, and confuses paedophiles accessing illegal content and consenting adults who are doing nothing wrong. We don’t think that this is the last word on the problems caused by adult content.