In the second report looking at privacy and the internet, Dan Simmons examines whether it is possible to be totally anonymous and asks if this is really a desirable thing.
In London's Speakers' Corner, the right to freedom of expression has been practised by anyone who cares to turn up for centuries.
Anonymous e-mail systems have been around for 10 years
But in countries where free speech is not protected by the authorities, hiding your true identity is becoming big business.
Just as remailers act as a go-between for e-mail, so there are services through which you can surf the web anonymously.
After 10 years in the business, Anonymizer has two million active users. The US government pays it to promote the service in China and Iran in order to help promote free speech.
But these programs are becoming popular in the West too.
The software encrypts all your requests for webpages. Anonymizer's servers then automatically gather the content on your behalf and send it back to you.
No humans are involved and the company does not keep records of who requests what.
However, there is some censorship. Anonymizer does not support anonymous uploading to the web, and it blocks access to material that would be illegal under US law.
No to censorship
For the last five years, Ian Clarke has been working on a project to offer complete anonymity.
Founder and co-ordinator of Freenet, Ian Clarke says: "Our goal was to provide a system whereby people could share information over the internet without revealing their identity and without permitting any form of government censorship."
The system is called the Free Network Project, or Freenet. A Chinese version has been set up to help dissidents speak out there.
Freenet encourages anonymous uploading of any material.
Some users of the English version believe it is so secure they have used it to confess to crimes they have committed, or to their interest in paedophilia.
Each user's computer becomes a node in a decentralised file-storing network.
As such they give up a small portion of their hard disk to help the system hold all the information and as with anonymous surfing, everything is encrypted, with a military grade 128-bit algorithm.
The storage is dynamic, with files automatically moved between computers on the network or duplicated. This adds to the difficulty of determining who might be storing what.
Even if a user's computer is seized, it can be impossible for experts to determine what the owner was doing on Freenet.
But such strenuous efforts to protect identity have two side effects.
Firstly, pages can take 10 minutes or more to download, even on a 2Mbbps broadband connection.
Secondly, the information is so well encrypted it is not searchable at the moment.
Forget Google, your only option is to scroll through the indexes provided.
It is hoped usability of the service will improve when it is re-launched later this year.
But those are the least of our problems, according to some experts, who think Freenet is a dangerous free-for-all.
Digital evidence expert at the London School of Economics, Peter Sommer says: "A few years ago I was very much in favour of libertarian computing.
Millions go online in China in internet cafes
"What changed my mind was the experience of acting in the English courts as a computer expert and examining large numbers of computers from really nasty people, who were using precisely the same sort of technology in order to conceal their activities.
"I think that creates an ethical dilemma for everyone who wants to participate in Freenet.
"You are giving over part of your computer, it will be in encrypted form, you will not know what you are carrying, but some of it is going to be seriously unpleasant.
Are you happy with that?"
What worries many, is that Freenet is a lawless area.
It can be used for many good things, like giving the oppressed a voice, but users can also preach race-hatred or share child pornography with complete impunity.
Peter Sommer says: "Ian [Clarke] is placing a powerful tool in the hands of other people. He's like an armaments manufacturer.
"Guns can be used for all sorts of good purposes but you know perfectly well that they are used to oppress and kill.
"Most armaments manufacturers walk off and say 'it's not my responsibility'. Is that Ian's position, I wonder?"
Ian Clarke response is to explain that any tool is capable of misuse.
"We believe that the benefits of Freenet, for example for dissidents in countries such as China, Saudi Arabia, Iran far outweigh the dangers of paedophilia or terrorist information being distributed over the system," he says.
Commercial programs for the web help you maintain a high degree of anonymity while surfing or mailing, but the realm of publishing anonymously, without fear of any comeback, challenges each society to ask just how free we want ourselves and others to be.
Click Online is broadcast on BBC News 24: Saturday at 2030, Sunday at 0430 and 1630, and on Monday at 0030. A short version is also shown on BBC Two: Saturday at 0645 and BBC One: Sunday at 0745. Also BBC World.