Britain's counter- terrorism supremo, Peter Clarke, has been speaking out against leakers. He has condemned those who leak counter-terrorism intelligence as "beneath contempt". He accuses such people of betrayal, and says they have compromised investigations by revealing details of life-saving intelligence. He claims their behaviour is directly connected to a damaging lack of public trust in intelligence.

Sadly, if understandably, he is not explicit about those he is condemning. Are they in his own service, the police? Or are they employees of the government, among the vast cohorts of spinners and media manipulators that have flourished during Blair's decade in power? Such people have always been with us; the art of spinning is not new. It is, however, in danger of becoming more of a disease than an art, especially, as has happened under this government, when human tragedy is seen as an opportunity to "bury" (a particularly unfortunate word) bad news.

Leaks of the kind Clarke attacked are corrosive. They lead to a climate of cynicism and suspicion, and a loss of trust in those who are protecting us from a genuine and present threat. Earlier this year, there was media frenzy when eight people were arrested in Birmingham in connection with what was widely reported as a significant kidnap plot by terrorists (it was not reported as an alleged plot by alleged terrorists). I was uneasy about this, as it coincided with the second arrest of Lord Levy during the cash-for-honours inquiry. His arrest was bad news for the government; the arrests could be dressed up as good news. At the very least, they were diversionary.

So my reaction was to link the two events. That was natural, in a society where there is widespread suspicion of constant and pervasive news manipulation by those in power. Those who are supposed to be safeguarding our liberties are eventually seen as a threat to these very liberties. This, in turn, leads to widespread suspicion about the rapid growth of surveillance by the state. It is now almost impossible, for example, to have a mature and reasonable argument about identity cards because we no longer trust those in authority.

It would be wrong to blame current government ministers for this climate, in which suspicion, paranoia and conspiracy theories flourish, but they have not helped matters. Enormous damage was done during the build-up to the calamitous Iraq war when there was disgraceful manipulation of intelligence.

The borders between the media and government are always complex and blurred. In the 1970s, I formed huge respect for a junior minister in Jim Callaghan's government.

This was the late, great Frank McElhone, a palpably decent man, if a somewhat eccentric minister. He represented to me everything that was best about old Labour. He was a man who put changing the world for the better before his own career, although in person he was utterly devoid of pomposity or self-righteousness.

He was in charge of Scottish education at a difficult time, not least financially. His attempts to change policy and launch initiatives were baulked by his advisers and senior civil servants at St Andrews House. Not surprisingly, he found allies in the press. He became friendly with three of us in particular, and started briefing us regularly about what was going on, and what he was trying to do. This went against the conventions and made him even more unpopular with his senior civil servants. But Frank believed sincerely that he was not briefing against them; rather, he was using us - and I admit we were used - to put forward his own ideas and aspirations, when he felt these were being unfairly frustrated.

I suppose this was a classic exercise in spinning, in the manipulation of information. I took part in it and was happy to do so. Therefore, people such as I should always be careful before we jump on to our high horses and rush to condemn governments and their media officers for spinning and even distortion.

There is now a new component in the mix, and that is the explosion of citizens' journalism. It would be ludicrous to regard the media prior to the advent of the internet as a pristine band of brothers, searching earnestly for the truth at all times. But we now live in a world in which misinformation, malice, conspiracy theories and powerful paranoia are being purveyed night and day in the so-called "blogosphere".

Professional journalists may not have been subject to many restraints apart from legal ones, yet the media has always been regulated, as any editor knows. Citizen journalists are not regulated at all, not subject to any restraints.

We could soon see the most unlikely alliance of all: an alliance between the old media and governments against the new army of bloggers.