A couple of weeks ago an armed gang took over Central Drive in the Creggan estate in Derry, placing men with automatic weapons at either end of the road while others threatened at gunpoint youths standing outside a row of shops, searched them and warned that they could expect no mercy if they stepped out of line again.

The gang claimed that before leaving the scene it fired 80 shots from automatic weapons to underline the seriousness of its intent.

I suspect that many in other parts of the north won't have heard of the incident. In contrast, a piece of playacting by 'dissident republicans' in a village in south Armagh a few weeks earlier had attracted widespread coverage and concerned statements from senior politicians.

The relative silence about the activities of the Derry gang can be detected in the name in which they have cloaked themselves: Republican Action Against Drugs.

Drugs. The very word seems to send otherwise sensible people into spirals of hysteria.

RAAD has shot 15 people in Derry in the last 18 months - dragged young men from their homes and maimed them in full public view, hurled a pipe -bomb at a terraced house, blowing out the living-room windows and wrecking a car, kicked their way into a home and forced a young man to lie on the floor to be shot. And so on.

The offence of the youngsters at Central Drive appears to have been hanging around outside the shops making nuisances of themselves. RAAD explained that their major operation "should be seen as a warning to young people who cause weekly mayhem in the Central Drive area. We would ask parents to take this warning seriously and advise their sons and daughters to stay away.''

The outfit had evidently extended its remit. Having come onto the scene proclaiming an intention to rid the town of drugs, it appeared now that they didn't have to suspect you of drug-dealing to make you a legitimate target. If they reckon you've been involved in anti-social behaviour, expect a bullet. And your ma and your da can whinge all they like. They should have kept you in, shouldn't they?

RAAD is a lineal descendant of Direct Action Against Drugs, which murdered 11 people in the Belfast area in the 1990s. The question arises: morality apart, if there is any validity in this approach, how come the drugs problem in Belfast is as bad now as it was then?

One reason the approach can be maintained has to do with the intense irrational alarm about drugs generated by Right-wing politicians and media outlets which has the effect of making anyone accused of drug-dealing seem fair game to people who would never approve of such cowardly maiming and killing in any other context.

The ideology behind RAAD can be found in profusion in the letters page of the Sun. Useless police, namby-pamby judges, prison a doddle, only language these people understand . . .

In January, RAAD shot a shop-owner in Derry three times for selling mephedrone. A demonstration against the shooting outside the shop attracted councillors and MLAs. So when news came in March of the mephedrone-related deaths in Scunthorpe of Louis Wainwright (18) and Nicholas Smith (19) RAAD's cup of joy overflowed. 'We wuz right', they crowed, jeering at those who had attended the demonstration.

The mephedrone angle had earned the story of the deaths of the Scunthorpe teenagers front-page billing. But there was hardly a cheep from the same outlets when toxicology tests revealed last month that there wasn't a trace of mephedrone in either youth's bodies. The drug found in dangerous concentration was alcohol. So no story there, then. Members of the Wainwright and Smith families had been subjected to television and newspaper interviews in which they were invited to plead with young people not to use mephedrone and to demand that it be banned. Responding to the furore, Home Secretary Alan Johnston announced that the Government would move with all haste to ban mephedrone. A bill was drafted and became law within a couple of weeks.

Two members of the Advisory Council on the Misuse of Drugs resigned in protest, claiming that the council had been subjected to 'intolerable' political pressure. The medical journal The Lancet warned against politics being allowed to 'contaminate' the appraisal of medical evidence.

Once again, drugs policy had been made on the basis of inaccurate information and accepted in an atmosphere of moral panic.

This moral panic is the mulch in which weeds like RAAD grow.