BT's plans to filter some websites set a dangerous precedent, warns technology analyst Bill Thompson
If you live in Saudi Arabia and want a tasteless joke to tell at a friend's party, do not bother searching the web for one.
Saudi Arabia censors the net
Bad joke sites, along with sites featuring swimsuit models, pornography, information about Middle Eastern politics or material felt to be hostile to Saudi Arabia are all on a list of banned sites, and you cannot see them.
The reason is that the government has decided to block sites with content "in violation of Islamic tradition or national regulations".
And if you try to visit one of the thousands of banned sites, you will get an official government page instead, telling you that it is blocked.
You can even fill in a form explaining why you think the site should be unblocked, and the government's Internet Services Unit will consider your request.
It is censorship, but it is honest censorship.
Freedom to filter
However, if you are a BT broadband customer and you follow a link to a website that is suspected of hosting images of child sexual abuse - what is often sloppily called "child porn" - then you will get a "page not found" error.
That is because BT has just introduced "Cleanfeed", a filtering program which silently blocks access to the websites on a list provided by the Internet Watch Foundation, the voluntary group that has become the government's favourite online policeman.
It is censorship, but it is a typically embarrassed and underhand British form of censorship.
The Cleanfeed list includes sites that IWF claim host images of child abuse which are, of course, illegal. It sounds like a good idea, and you can see how the people who are responsible for BT's security policy would have found it appealing.
But the announcement instantly raises many questions.
Some are obvious: Why are customers not told the site they are trying to access is blocked? Who is responsible if a legitimate site is added to the list? And how can you get off the list if you cannot tell your site has been blocked?
More importantly, what is to stop BT silently adding other categories to its blocked list?
Perhaps race hate sites, or sites that tell people how to hack the Cleanfeed service itself. And what will the company do if the government asks them to block access to a site hosting leaked documents, since they are just as illegal as child pornography?
BT has said it no plans to extend the project beyond child porn sites.
Because the announcement is about child abuse, anyone who dares to challenge it is instantly under suspicion as a supporter of paedophiles. But this should not stop us pointing out that Cleanfeed is a bad idea and must be stopped.
This is not just because it will not achieve its goal, although it seems that it will be easy to get around, but because it sets a precedent for ISP control over what their users can do online that is simply unacceptable.
Unlike Saudi Arabia, freedom of expression is fundamental to our society, and blocking websites in this way defies that tradition and must not be allowed.
Last weekend I had an argument about the core principle of online freedom of speech with Cory Doctorow, who works for the digital rights campaigning group, Electronic Frontier Foundation.
Cory Doctorow: free speech fundamentalist
Despite being Canadian, Cory is a First Amendment fundamentalist when it comes to online speech. He argues that once you have a system that allows you to separate "good" bits from "bad" bits, then that system will end up being extended and abused by those in power.
For him, and many other net activists, the dangers of censorship are always greater than the risks that come from leaving speech free.
I am more of a pragmatist, and I have argued many times before that it is acceptable for governments to regulate our speech online just as they can regulate our speech in the real world.
They just have to do it in a way that is open, accountable and subject to the democratic process.
Race hate, images of child abuse, obscenity and other forms of speech are already controlled, even online.
Some years ago most UK internet service providers decided that they would stop providing their customers with access to a number of Usenet newsgroups that were being used to share images of child abuse.
But there is a fundamental difference between blocking websites and restricting access to newsgroups.
If your ISP does not provide a particular group then you can look for other news servers which do have the group you want, or use the Google news archive, but if your ISP is blocking particular websites then you cannot get round it without getting a new ISP.
And if you do not know what is being blocked, then you cannot argue or campaign or ensure that the sites blocked are only those which the law properly covers.
So here I agree with Cory. It is better not to have any websites blocked and take the risk of openness than to allow blocking by ISPs and risk the consequent "mission creep" and loss of freedom.
There is already a technology which would allow individual control over which sites can be viewed.
It is called Pics, the Platform for Internet Content Selection, and allows for every website and even page to be rated so that browsers can decide whether to display them.
Pics raises issues of free speech too, especially when it comes to having to rate education sites, or news sites like BBC News Online, since they may have images of violence, nudity and even bad language.
However, it has to be a better approach than leaving the power to filter in the hands of an unaccountable voluntary organisation and a bunch of ISPs who are there to defend shareholder value and profits, not our online freedoms.
Bill Thompson is a regular commentator on the BBC World Service programme Go Digital.