Technology replaces the twitching curtain: Amateur eavesdropping is becoming big business. Simon Beckett listens in

'SCANNERS are very, very big,' says Alan Hooker, an amateur-radio dealer in South Yorkshire. And getting bigger every week. Amid the furore of Camillagate and the Calcutt proposals to clamp down on the press's use of long lenses and bugging, the little gadgets that sparked the whole thing off are still on general sale. Since the 'Squidgy' tapes affair, in which a retired bank manager was alleged to have recorded a conversation on a radio scanner between the Princess of Wales and an admirer, scanners have become the modern equivalent of the twitching curtain - the base desire to know what other people are up to.

Sitting in his office, Mr Hooker is constantly interrupted by customers and telephone inquiries. Some of these are for ham radios. Most are for scanners. 'In these recessionary days, I wouldn't like to be without them,' he says. Tandy, one of the major stockists of scanners, is more coy, admitting only that sales are 'steady'.

Scanners themselves are not illegal, and do not even require a licence. They first appeared in the UK in the mid-Seventies, when their main buyers were aircraft enthusiasts who used them to eavesdrop on civil aviation frequencies. Now they have become much more sophisticated, and much more in demand. Similar in appearance to mobile telephones, and with a range of about five miles, they can be bought in the high street for about pounds 300 and are quite simple to use. Specific frequencies can be entered into the scanner's memory for easy recall, and if an exact frequency is not known they can 'search' through the waveband until they find and lock on to a transmission. They can be legitimately used to tune into such essential listening as Citizens' Band Radio, public radio broadcasts, and the weather report on ship to shore. But it is illegal to use them for listening to official or private conversations. Which is, of course, exactly why most people buy them.

Conviction for illegal use of scanners carries penalties from seizure of the scanner to two years' imprisonment and an unlimited fine. But the sheer number of people now using them makes effective policing virtually impossible. 'One problem is that scanners don't transmit, so you can't detect them by monitoring,' a Department of Trade and Industry spokesman says. 'Normally, they are detected by police when they're investigating another criminal offence, and by chance they discover that the scanner is being used for criminal purposes.'

One of these 'criminal purposes' is their use by burglars as early warning devices to keep track of police movements by listening to their transmissions. But most scanner users would probably say that, although they are technically breaking the law, there is no harm in what they do.

'These people aren't dangerous, they just sit at home earwigging,' says Mr Hooker. His customers range from young boys to old ladies, who see scanners as an alternative to peering through the curtains at the neighbours. 'I got one bloke in; he said his wife had sent him down to buy a scanner. They'd just moved into the area, and he said they wanted to know what was going on around them.'

To assist your friendly neighbourhood scanner, there is a UK scanning directory, giving such helpful frequencies as Airport Security, British Nuclear Fuel Incident Channel, USAF Bomb Disposal Units, and Ministry of Defence Tactical Communications. While it is illegal to listen in to any of these frequencies, it is perfectly legal to publish and sell them. The directory has been censured by the press and MPs, but remains extremely popular with scanner enthusiasts themselves. After only a year it is already in its second edition. 'It's what people want, and that's what we produce,' says Richard Barnes, of Interproducts, the directory's publishers. He refutes any suggestion that it could be used by criminals or terrorists, arguing that since the frequencies are supplied to them by amateur enthusiasts, they are hardly likely to pose any real threat to national security. 'How can they? Joe Public doesn't have a GCHQ set up in his back garden.'

In fact, all the listed frequencies have been publicly available for some time; the directory merely compiles them in one volume. Nor are they high-priority ones. 'In Northern Ireland, one of the channels is actually used for BBC outside broadcasts,' the DTI spokesman says. 'Sensitive conversations are not carried out on equipment that can be easily intercepted.'

The directory is not the only source of information available to enthusiasts. I recently received a 10-page photocopy from an anonymous source, giving what appears to be a detailed breakdown of the South Yorkshire Police communications system. It warns that the information is for 'instructional purposes' only, not to be used in conjunction with a radio scanner, and goes on to list the call signs and frequencies of everything from response cars to the West Yorkshire police helicopter. It is so detailed that even the colour, type and registration number of the chief constable's car is included, along with the fact that the Regional Crime Squad's main radio operator, now retired, was an old lady called Doris.

Although the police are aware that similar material exists for forces all over the country (compiled and exchanged, they believe, by scanner enthusiast clubs) there is little they can do about it. Some of the more sensitive departments such as Special Branch already encrypt (scramble) their transmissions to prevent them being monitored. This technology is not currently available for the majority of police radios, though it will not be long before it is introduced.

But if the police and military can at least scramble or use coded messages to thwart would-be listeners, that is hardly an option for the average car phone owner. The 'Squidgy' tape, whether authentic or not, demonstrated how vulnerable mobile telephones are. Any scanner within receiving range will be able to pick up both sides of a conversation, yet many people still believe mobile phones offer them the same degree of privacy as normal, fixed-line telephones. The following extract gives some idea of the sort of tidbit random eavesdropping can produce.

Man: Did you go out last night? Eh?

Girl: What did you wake me up at half four for?

Man: Because I wanted to know where you were]

Girl: Where were you?

Man: I was at home.

Girl: Were you hell, you were in the car]

Man: I know, I was on my way home. Where were you? Where'd you been? Where did you go . . . on Wednesday night?

Girl: I didn't go anywhere]

Man: You lying bitch]

'People on car phones really ought to be wise that there are millions of people listening into them,' Alan Hooker claims. 'Millions. Most business people, and an awful lot of high-up people, shouldn't be talking on them in the way they do.'

Whether the listeners view such an invasion of privacy as 'harmless' entertainment or have ulterior motives, there is little defence other than ensuring that our conversations are so boring no one would want to listen to them. There are no plans to tighten legislation on scanners, and the question of morality seems to be a lost cause. Eavesdroppers clearly see nothing wrong in it, while dealers argue that radio scanners are a legal - and lucrative - business. 'I have no bloody interest in 'em,' says Mr Hooker, cheerfully. 'I just sell them.'

(Photograph omitted)