Big Brother delves into your inbox

One in 500 of us could be being spied on in future

By BBC News Online's Jenny Matthews

Student Julie Ann Davies was "astonished" when she was arrested over her links with former MI5 spy David Shayler, because she'd had no idea she was under police investigation.

It is speculated that she had been the subject of a covert operation, and that police or MI5 had been intercepting her e-mails for some time, entirely without her knowledge.

Every website you visit can be legally monitored

The case comes just weeks after revelations about Echelon, a global satellite intelligence system which apparently "hoovers up" all our communications, including e-mails, for governments to study.

So exactly how easy is it for the police, MI5 and other state authorities to snoop into our e-mail inboxes and outboxes?

ISPs

The main piece of legislation currently covering such things is the 1985 Interception of Communications Act.

This allows the police and security services to tap phone lines or intercept paper mail, after obtaining a warrant from the Home Secretary (or the First Minister in Scotland), the Foreign Secretary, or the Northern Ireland Secretary.

MI5: Monitor thousands of people each year

But because the law was made before the boom in electronic communications, the situation is complex.

E-mail spying is done via the 300 or so UK ISPs, which the law requires to fit equipment and allow access to lines for this purpose.

ISPs who are also licensed telephone operators - such as AOL or MSN - are covered by the Act, and therefore agents can access e-mail "on the move", or as it is being sent, through these systems.

Others are not licensed telephone operators and therefore not covered by the legislation for e-mails as they are being sent.

Here, according to Dr Yaman Akdeniz of Cyber-Rights and Cyber-Liberties, police or the MI5 can use the Data Protection Act to gain access to stored e-mails.

Who's being watched?

About 2,000 warrants are currently issued each year, and the Home Office has told ISPs that in future they should be able to intercept one telephone line for every 500 lines that they operate.

This means, even using conservative estimates of how many of us are going online, the potential to tap an awful lot of e-mails.

Moreover, the number of wiretaps is widely expected to soar when new, replacement legislation comes into force.

Mobiles are included in the Investigatory Powers bill

The Regulation of Investigatory Powers Bill (RIP), currently going through the Commons, is aimed at updating the 1985 Act to keep pace with new technology.

For the first time, it will formally regulate covert surveillance of all new communications, including all types of mobile phone messages, pagers, and e-mails.

Of course, that doesn't mean surveillance of these technologies hasn't been done on a large scale before. Even Jack Straw admits it will just replace "old, non-statutory, less formal methods".

All this comes after the Echelon claims

But civil liberties groups are seriously worried about several major aspects of RIP.

One is that for the first time it explicitly allows surveillance by other authorities, such as the DSS when investigating benefit fraud, or the Inland Revenue probing a suspected tax fraud.

Another is that it will allow for "traffic data" to be monitored - something not covered by the 1985 Act.

That means that police and security agencies can look at data such as which website or chat-room you have visited, including password information.

And this bit of surveillance, says Malcolm Hutty, director of the Campaign Against Censorship of the Internet in Britain (Cacib), can be done without a warrant.

Can I hide the info?

Information gathered clandestinely is still not admissible in court, it can only be used to point to a conviction.

But if you don't want to be spied upon, you can try encrypting your information so that it can only be accessed with a special software key.

However, a highly contentious part of RIP requires individuals to hand over the information or the key to the authorities on request - or prove that they don't have access to the key.

Campaigners say this is an impossible defence, and places a negative burden of proof on the person being watched, whereas the law usually presumes that you are innocent until proved guilty.

If you had a complaint about the way your surveillance was being handled, RIP establishes a new complaints tribunal.

However, you are highly unlikely to be in that position - as the person being monitored is never told about the surveillance.