Well, if Claire McEntee were a better journalist, she would have asked some rather pertinent questions. Here are mine:
1. What is the definition of child porn? Does the software block all "objectionable" material, which goes well beyond what people commonly think of as child porn, but also includes adults wearing school uniforms roleplaying and includes erotic stories about legal acts between adults? How focused is it? Who is really going to lobby for erotic material that is legal to be let through?
2. Isn't the bigger problem those who abuse children and in the course of that video/photograph it and distribute those images, and doesn't this do absolutely nothing to stop it (it just stops people seeing material others produce)?
3. How does DIA respond to the report in Wired that an increasing problem is law enforcement agencies finding that much "child porn" is produced by the "children" themselves with camera phones - the children being teenagers who are underage. Such behaviour is foolish and should be discouraged, but not exactly what the law should be prosecuting.
4. What is the scale, extent and main geographic sources of the real child porn problem? That means those who are underage who are abused and have images taken of this abuse and distributed. How much material circulating is decades old (when such material was sadly legal in some European countries and poorly enforced elsewhere), how much is produced in developing countries, Russia or Ukraine where law enforcement has other priorities, how much is material swapped between child rapists, how big or small is the alleged "industry"? After all, what fool would pay for illegal material online when any payments can easily be traced?
Nobody knows because nobody can undertake research on the topic without becoming a criminal, and some law enforcement/censorship agencies have institutional interests in seeking increased funding to address the problem. It is perhaps the only area of the criminal law where research is effectively closed.
Let's be clear. Laws relating to censorship should shadow those related to crime. Images of what consenting adults do (or stories) should not be a subject of the law. Real child porn - images of those under the age of consent as victims of sex crimes - is appropriately the business of criminal law, as those producing it are accessories to the crime itself. However, there needs to be some genuine open discussion about what the business of the law is, what is the extent of the problem and ensuring that measures to address the real problem,are not sledgehammers to crack a nut.
In that context, if ISPs want to purchase software to block sites, then let them feel free to do so. However, it should not be a trojan horse for censoring more than material produced in the context of a real crime.