It has become an intelligentsia default position, or IDP for short, that we in Britain are - as one of my favourite intellectuals put it the other day - “sleepwalking into a surveillance society”. The Oxford academic and writer Timothy Garton Ash told a BBC interviewer that more information was now collected by the State on British subjects than was available to the East German secret police, or Stasi, from their army of informers.

I hear this all the time. A very clever person said to me at the weekend that the ubiquity of CCTV meant that she felt “constantly watched”. This too is an IDP. It shouldn't have surprised me then that last week a pitbull national radio interviewer failed to ask the most basic question of a woman who was arguing for the dismantling even of the DNA database that we currently possess.

He could have asked her about the case of the Dearne Valley rapist, for example. Between 1983 and 1986 James Lloyd raped four women and attempted to rape two others in South Yorkshire. He was never caught, his victims never received any kind of justice, nor was society protected from him. Until, in 2006, a cold case review led to the attacker's DNA being closely linked with 43 samples on the national DNA database. One of those was Lloyd's sister, whose DNA had been taken when she was convicted of drink-driving in 2000.

Yet no such question was put, and in part I credit the director of Liberty, Shami Chakrabarti, with the creation of the atmosphere in which such a challenge was flunked. Ms Chakrabarti is probably the most effective public affairs lobbyist of the past 20 years, certainly since Des Wilson hung up his boots. Her argument is that, given the intimate nature of DNA extraction and the possibility of abuse or error in any system, the only DNA database we need is of “those who have been convicted of sexual and violent crime”.

This view may yet prevail. The UK DNA database is already one of the largest in the world, mostly because, for the past few years, the police have been allowed to take and keep a swab from anyone arrested for a recordable offence. But on Thursday the European Court in Strasbourg will rule on a case brought by two Sheffield people, both of whom were arrested for offences and subsequently cleared, but not before their fingerprints and DNA were taken. If they win, then 13 per cent of the records currently on the UK database may have to be destroyed.

The police, of course, would be very unhappy. The use of DNA evidence in tracing and - last week - convicting both the Ipswich murderer Steve Wright and the necrophiliac Mark Dixie was further proof, as far as they were concerned, of the benefits of as large a database as possible. Wright was identified from DNA taken when he was charged with stealing £40, and Dixie was immediately identified when DNA was taken after he'd been involved in a pub brawl. Had there been a national universal database, said one policeman, Dixie would have been caught nine months earlier.

This officer was then accused by Ms Chakrabarti, in a display of genuine chutzpah, of “using high-profile cases like the murder of Sally Anne [Bowman] to showboat”, and a spokesman from another group, Justice, spoke of the “grave injustice” of using the Wright case to argue for the taking of samples from “innocent” people.

But what of the trade-off? Garton Ash hinted that there was one when, in a recent article, he rather uncharacteristically told “nanny” that she could “eff off to East Germany. I'd rather stay a bit more free, even if it means being less safe.” In the case of shrinking the DNA database that preference would certainly leave Lloyd still unpunished for rape and Steve Wright quite possiblycould have killed again.

So would Garton Ash really rather be freer and less safe to the extent of having less chance of catching a rapist or murderer? It's a brave position, but he and other upholders of the IDP should now be asked to spell it out. Then we would see that one problem is how to assess the rights of victims of crime, as well as potential victims. How do we measure my right not to feel discomfited by CCTV or DNA testing, against that of, say, Justine Kelly, who was 18 - one year older than my oldest daughter - when she was raped by Lloyd, and who said that seeing him sentenced “and facing a life sentence has helped me to finally feel at rest”.

As it happens I don't feel “watched” by CCTV, and I think it is a paranoid fantasy to imagine that we are “under surveillance” in the way that informers kept the Stasi up to date with the conversations of their subjects. I also believe it is perverse to shun biometrics that merely give real effect to ineffective measures we have long taken in this country, such as insisting on car numberplates and passport photos. “We should not hold information on innocent people,” says that unlikely IDPer, David Davis, the Shadow Home Secretary, lest we become “a nation of suspects”. On that basis let us burn our passports and smash our numberplates.

As to innocence, well most of us are innocent. But Lloyd's family never suspected him of rape, Wright's wife was sure he couldn't be a murderer, and Dixie's friends had not an inkling of his capacity for extreme sexual violence. There has never yet been a would-be bomber whose family didn't proclaim his normality.

So we'll want something. But the trouble is that when we make some databases arbitrary, as the DNA database currently is, then we effectively discriminate between citizens. After all, a pub brawler is not, per se, a sexual murderer, nor is a casual embezzler a serial killer. A database of existing offenders in particular categories also means that certain ethnic groups are far more likely to be recorded than others, and therefore are far more likely to be successfully prosecuted in future. The Sheffield appellants case is partly based on a claim under Article 14 - the right to non-discrimination - of the convention.

This was why, in September 2007, Sir Stephen Sedley, one of the judges at the original appeal, argued that the existing system was “indefensible” and called for an extension of the database to all British citizens and UK visitors. For which, of course, he was immediately set upon. But I think he was right; and no, I won't eff off to East Germany.

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