Big brother really is watching us all

TECHNOLOGY is changing the way the police work, creating powerful new tools to control crime. In 15 years, many types of crime could be largely eliminated. However, the tools for this also open the door to sinister Orwellian possibilities. Our privacy could be destroyed, with officials able to snoop at will on our lives.

There are four million CCTV cameras in Britain, with the number set to rise and rise. They have had a considerable impact on crime, but this is nothing compared to their potential if projects to create "smart" CCTV cameras are successful. Smart cameras could recognise criminal or anti-social behaviour, and alert the authorities. They could also be hooked up to a database of photos (eg those collected for ID cards) and used to automatically track the movements of people, which currently requires a (junior) police officer to spend a lot of low-quality time watching footage duller than the cricket.

Several councils are already experimenting with linking CCTV systems up with such software, though so far the technology has failed to live up to the developers' claims.

Elsewhere, computer sleuths might identify likely criminals by their habits. In modern society, it is increasingly hard to move without leaving behind a trail of electronic fingerprints: mobile phone networks track your position, CCTV cameras video your actions, credit-cards record your purchases, phone calls can be monitored, and your internet use is logged. These e-prints can be searched for patterns associated with crime.

Pattern-learning software is already used by credit card companies to detect fraud. Similar techniques could be used to spot criminal or terrorist-like behaviour. Such systems could quickly identify suspects, and hence focus stretched police resources. It is important to remember that behaviour "similar to that of criminals" is not evidence of guilt, because this government is quite capable of locking people up on such grounds.

Having been caught by computer, a suspect might then be tried by one, at least partially. This seems peculiarly terrifying in a Kafkaesque way: What if the machine makes a mistake - how would anyone know? When you think about it, this is no worse than being wrongly imprisoned by a jury, and the idea is to reduce such mistakes. Individual pieces of forensic evidence are often inconclusive. A CCTV image shows a figure, but how reliably can it be identified? Microscopic particles of broken glass on the suspect's coat, a strand of fibre at the scene which matches - but what does it mean? Adding up these fragments of evidence is a challenging task, requiring a team of experts. Make a mistake and an innocent man could go to jail - or a killer could go free.

We humans are distressingly poor at using technical evidence, probably because it lies outside our direct experience. This was shown in the tragic case of Sally Clark, who lost two babies to cot death and was then falsely convicted of their murder on the basis of a mistaken statistical calculation.

This is where computers come in - they are very good at calculating the kind of probability-based problems that forensics throw up.

There's a Scottish project to develop this idea into a usable technology. It involves pooling the knowledge of forensic scientists to build an "expert system"; a computer with an in-depth knowledge of forensics.

All of this is rather scary. It places powerful snooping tools in the hands of government. Of course the authorities have always had the ability to pry. Previously our privacy was protected by legal safeguards (eg warrants used to be required for phone taps). But the biggest safeguard was the cost: investigating an individual took up considerable resources. Soon it may be possible for police or civil servants to browse through your affairs in much the way I browse the internet: sometimes for legitimate reasons, sometimes for idle amusement.

The potential for abuse and corruption is huge. These tools are not limited to preventing crime. They could be used for blackmail, or spying for all kinds of purposes, personal, political or commercial.

New safeguards are needed to handle the new technology. Private information should be protected. Defendants should have access to the systems used to accuse them; CCTV can be used to prove innocence and guilt. Given a fair, accountable system, new technology will be a great boon. With the current government pushing us towards less openness and accountability, safeguards to protect the public seem unlikely. So what does the future look like: less day-to-day crime, but more state-control and corruption. Consequently I am worried, but well-behaved.