Ventilation grill or one-way mirror: Cameras don鈥檛 have to be small or expensive to take covert images. A standard video camera could fit behind a ventilation grill, and a device known as a videosender could broadcast the images in a form that a standard television set could pick up a few hundred metres away.
Equipment needed:
Video camera and videosender
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Cost: Camera 拢200, videosender 拢40
Legality: Camera legal, videosender illegal to use
Availability: Camera from any electronics retailer, videosenders by mail order in the UK
Television: Televisions leak electromagnetic signals that can be used to reconstruct the picture on the set. This is how television detector vans can tell what you are watching. An electronics expert could build a similar detector and tune in to your home videos as you watch them, look at the data displayed on your computer screen, or even monitor visitors on a video entryphone.
Equipment needed:
Home-built
Cost: Under 拢100 for components
Legality: Probably illegal to use; legal to buy and sell
Availability: Parts available from electronics suppliers
Telephone/fax machine (1):
Conversations can be recorded by a voice-activated tape recorder the size of a packet of cigarettes. It could be connected to the telephone junction box or an extension point in another room
Equipment needed:
Voice-activated tape recorder
Cost: 拢50
Legality: Illegal to use in certain circumstances; legal to buy and sell
Availability: Any spy shop
Telephone/fax machine (2): Fax messages can be recorded, but this needs a high-fidelity tape recorder, which tend to be bulky. A transmitter in the telephone junction box can broadcast the signal to a recorder outside
Equipment needed:
High-fidelity sound recorder, miniature radio transmitter and receiver
Cost: 拢4000
Legality: Illegal to use; legal to buy
Availability: By mail order from Germany
Telephone/fax machine (3): Pick up the nearest phone and dial 1471. The chances are you will hear a recorded message announcing the telephone number of the person who last called, even if their number is ex-directory. Devices that automatically display and store the number of every caller are freely available
Equipment needed:
None, apart from an ordinary telephone and BT account
Cost: Free; 拢50 for the automatic display
Legality: Legal
Availability: phone shops
Window:
Sound waves from conversations inside a room cause windows to vibrate.
Eavesdroppers can listen in by bouncing a laser beam off the glass and measuring the way it is modulated by the vibrations. The technique is extremely difficult to perfect since wind, rain and curtains mask the signals, but it can be done
Equipment needed:
Home-built
Cost: 拢200 to 拢300 for components
Legality: Probably illegal to use; legal to buy
Availability: Parts available from specialist electronics suppliers
Computer/briefcase video camera: In May this year, a Finnish au pair took her English employers to court, alleging that they had secretly videotaped her in her bedroom, undressing, emerging from the shower and enjoying intimate moments with her boyfriend. The camera was hidden inside a computer. Other favourite places to hide cameras are behind the sound grill on a television set or inside a portable briefcase
Equipment needed:
Miniature video camera
Cost: 拢1000 plus
Legality: Illegal to use in certain circumstances; legal to buy
Availability: Any spy shop
Table: Miniature microphones and transmitters can be hidden within an innocuous piece of office equipment such as a phone, a calculator or even a pen
Equipment needed:
Miniature radio microphone (bug) and receiver
Cost: From 拢60 to 拢2000 including receiver
Legality: Illegal to use; legal to buy and sell
Availability: Any spy shop
IF YOU think that secrecy is guaranteed in your bedroom or boardroom, think again. Use an analogue cellphone or a cordless handset, for instance, and almost anyone can listen in. And since portable phones are miniature transmitters they can easily double as covert listening devices.
A mobile phone is perfect as an easy-to-use bug, says Peter Clements of Templeplan Security Systems, a countersurveillance company in Kings Langley, Hertfordshire. Anyone can walk into a meeting with a mobile phone switched on and a tape recorder attached to the other end of the line. 鈥淣early all firms with more than 250 staff are at risk,鈥� says Clements, who has developed a technique for continuously monitoring up to 10 rooms for bugs. The system listens to the noises in each room and scans the airwaves looking for a radio signal containing the same sound pattern. If it finds a match, there must be a bug somewhere. Even a mobile phone would not go undetected, he says.
Clements can even spot 鈥渄ead鈥� bugs that have stopped transmitting, by looking for key components of their electronics circuits. All microelectronic devices, including those used to build tiny transmitters, contain trnsistors and diodes. When bathed in radio waves these components reradiate a harmonic wave with double the frequency. So Clement鈥檚 detector broadcasts an 800-megahertz signal, and listens for a response at 1600 megahertz. Telephones, computers and calculators all respond, of course. But if an ashtray, pen and paperweight behaves the same way, something is amiss.
People can go to enormous lengths to spy on others. Conrad Sandler, who runs the Spycatcher shop in central London which specialises in surveillance and countersurveillance equipment, tells a story about one of his customers. The young man was about to leave on a trip to California. While he was away, the man wanted to keep tabs on his girlfriend in London, who lived in a flat that he owned. Sandler supplied several bugs, a receiver that could listen to the transmissions from them all simultaneously and a computer to log the information. To house the receiver and computer, Sandler鈥檚 customer bought the flat next door.
From the US, the man could log onto the computer and see a list of all the conversations that had taken place over the previous 24 hours. 鈥淚f there had been a conversation in the bedroom at 2 o鈥檆lock in the morning, he could click on that entry and hear the conversation,鈥� says Sandler. The system Sandler sold him cost 拢37 000; the flat next door was extra. Similar systems are now very popular with the security services, says Sandler.
But such expense may not be necessary. To listen in to some cordless phone conversations takes nothing more sophisticated than a 拢10 AM radio. In cordless phones, the base station that plugs into a standard telephone wall socket is linked to the handset by a simple analogue radio link. Transmissions between the handset and base station are 鈥渃lear鈥� or unencrypted, so a standard radio receiver can pick them up. If your house is on a hill, the signals can travel several kilometres. Once an eavesdropper has your frequency, he or she can listen in to every call you make.
Analogue cellphone conversations are a little harder to tune into. The signals are clear, and an ordinary radio receiver can pick them up, but unlike a cordless phone, a cellphone does not use the same frequency for each call. Instead, it hunts for vacant frequencies each time it is used, so there is no way a snooper can tune into a specific telephone and listen to every conversation. But a radio receiver called a 鈥渟canner鈥� does the next best thing by sweeping through the part of the radio spectrum used by cellular phones, searching for a strong signal. When it finds one, the user can lock onto it and stay with the conversation until the caller hangs up. Scanners that cover the 900-megahertz band used by cellphones costs under 拢200 and are widely available.
Digital cellphones are much less of a risk. Hutchison鈥檚 Orange, Mercury鈥檚 One-2-One and the pan-European GSM services offered by Cellnet and Vodafone all rely on digital signals. On ordinary radio all that can be heard from these transmissions is a high-pitched buzz. To protect privacy further, these services scramble the signals using an encryption system that can only be decoded by the phone receiving the call.
The encryption is so powerful that governments in the West are worried about it getting into unfriendly hands. The technology cannot be sold to certain countries, such as Iran, Iraq and China, because Western intelligence agencies want to be able to eavesdrop on their broadcasts. Similarly, law enforcement agencies within the US are hoping that when digital cellphone services are introduced there next year, conversations will be unencrypted or only lightly encrypted so that they can eavesdrop on criminals such as drug traffickers.
Could anyone be eavesdropping on you? If you鈥檙e worried, Sandler or Clements will sweep your bedroom or boardroom for bugs. Prices start at 拢250, and for 拢950 you can buy your own bug detector. But try to keep the risk in proportion. Sandler says that people worried about being bugged far out-number those who are actually at risk. 鈥淲e sell 20 bug detectors for every bug鈥�, he points out. There鈥檚 a fine line between prudence and paranoia.
