It's not insane to be paranoid. That is the comforting message I took from the speech given this week by Sir Ken Macdonald, the Director of Public Prosecutions, who warned the Government not to abuse its “enormous powers of access to information”. In a direct hit on the Home Secretary's desire to record on an Orwellian database every e-mail, phone call and website visited, he said that “freedom's back is broken” if ministers give in to the pressures of a State that is insatiable.

I say comforting, because I frequently feel that I am living in a looking-glass world, where what Sir Ken calls the “paraphernalia of paranoia” makes reality feel like a spoof. Take a parochial example. Several readers sent me an article from the Lincolnshire Echo that claimed Lincoln City Council was training its plumbers and electricians to spot child abuse. I contacted some nice people at the council last week, apologising for wasting their time on what, I said, was probably overexcited gossip. But it turned out to be true. These perfectly sane people are indeed training their 820 staff to “recognise when a child may be in a harmful situation”. They believe that the Children's Act 2004 requires all employees to “safeguard and promote the welfare of children and young people when discharging the council's functions, eg, throughout their daily work or work that has been subcontracted out”. Staff will be trained, and required to “report to relevant agencies” what they see.

So the bloke who used to fix your washing machine on the estate, who would surely have called the police if he had seen a starving and beaten child, will become a subcontractor “accredited” by the local Safeguarding Children's Board. He will report any child wearing long sleeves in summer (one sign of possible abuse that trainers teach people to look out for, in case the sleeves conceal a bruise).

What, you might ask, is wrong with that? In a world where, the NSPCC never misses the chance to tell us, children suffer and no adult can be trusted? What is wrong is that this kind of well-meaning, covering- our-back kind of exercise will generate “information”. On which someone will feel he or she must act. The “information” may stay on file despite all attempts by the innocent family to rub it out. Meanwhile, the piles of paper on the desks of harassed social workers will grow higher. And people who never asked to be social workers will have been co-opted as informants against the taxpayers who pay their salaries.

I was once an advocate of joined-up government, because I wanted efficiency. But too often joined-up government seems to mean joined-up fascism. In June, a select committee of MPs heard some astonishing evidence from respected campaign groups. One, Parents Against Injustice, gave instances where people whose children were being taken into care had not been allowed to challenge the allegations against them. The Association for Improvements in the Maternity Services (Aims), said that midwives were being turned into “health police”. Jean Robinson, of Aims, said that she had seen case after case where health visitors and midwives were not supporting postnatally depressed mothers but reporting them to police and social workers, whose interventions largely made things worse.

In my investigations into child protection I have repeatedly come across doctors and psychiatrists who are expected to report suspicions of child abuse to non-medical authorities. One result of this “information-sharing”, it seems to me, is that the age-old principle of patient confidentiality is routinely broken - without a murmur from the medical profession.

I recently went to meet Mrs Robinson, in Oxford. She is one of the sanest, most reasonable people you could meet. She has lectured on medical ethics and sat on the General Medical Council. Yet like Sir Ken Macdonald, she uses strong language. Because that is the only way accurately to describe a State that has lost its sense of proportion.

The problem is not the Government's desire to build up a picture, so much as how that picture can be distorted. I have spoken to a number of families who say that it has taken years to get papers that the local authority holds about them, despite freedom of information and Data Protection Act requests. Mrs Robinson says that she has “never had a single case where social services provided all the information that a parent was entitled to within the time limit”.

The bitter irony is that none of this makes anyone safer. The Government is building a Children's Database that will contain the personal details of every child. Apart from the vulnerabilities involved in giving so many bureaucrats access to that database, it will also make the haystack gigantic. The real needles will be even harder to find.

The same problems beset the terrorist issue. The Government has been unable to point to a single case where 42-day detention, or increased surveillance powers, would have made us safer. Police officers can already get information on most suspects' phone calls and e-mails from network providers. The suspicion is that the Government wants to hold that data centrally only to mount fishing expeditions, looking for patterns of behaviour.

“We should take very great care to imagine the world we are creating before we build it,” Sir Ken said. “We might end up living with something we can't bear.” Even if Jacqui Smith drops her plans to make Big Brother everyone's Facebook friend, we have built something unbearable: built-in suspicion of citizens by the people paid to serve them.

We must not allow the Britain that we know, built on centuries of freedom, to be whittled out of existence by the sharing of “information” that is created by the State, controlled by the State, and that turns perfectly decent people into informers. You think I'm paranoid. But maybe I'm sane, too.

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