Digital Surveillance: Tools of the Spy Trade

Night-vision cameras, biometric sensors and other gadgets already give snoops access to private spaces. Coming soon: palm-size "bug-bots"

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  • DIGITAL STILL AND VIDEO CAMERAS fitted with large telephoto lenses make it possible for agents to discern the details of a faraway scene. An operative wielding a telephoto camera can read a newspaper headline (and, perhaps, subheads) from a football field’s length away.

  • NIGHT-VISION GOGGLES or telescopes fitted with photomultiplier tubes can dramatically brighten available light; thermal sensors can reveal warm bodies and hot engines in total darkness.

  • VOICE, facial features, walking gait and other characteristics can identify a person whose physical or behavioral traits are registered in an existing database.

  • DNA SENSOR, one of the latest biometric systems, samples DNA left, say, on a glass or doorknob and compares it with genetic information on file.

  • ARTIFICIAL NOSE detects a subject’s body “odor print,” which is matched against records.

  • DIRECTIONAL MIKE, assisted by a parabolic dish or a “shotgun” (linear wand), can pick up open-air conversations from several hundred feet away.

  • BUG, a tiny, hidden microphone and short-range radio transmitter, sends conversations to a radio receiver, which relays the speech to a recorder or headphones.

  • LASER BEAM bounced off a window can detect vibrations of the glass produced by the sounds of indoor conversations. An optical receiver converts patterns in the reflected beam into sounds a snoop can hear.

  • CHEMICAL MARKERS placed at a site attach to subjects when they touch or step on them.

  • GPS LOCATOR receives signals from the Global Positioning System and pinpoints a vehicle’s or person’s location to within six feet.

  • ELECTRONIC TOLL TAKERS, such as E-ZPass, enable authorities to monitor vehicles as they pass checkpoints.

  • PHONE TAP is a set of wires spliced into a junction box or phone line. Part of the signal branches into the tap, making remote listening possible.

  • COMPUTER TAPS, techniques that intercept e-mail, overhear voice communications or “sniff” keystrokes, permit spying on computer operations.

  • CELL PHONE MONITOR, a radio receiver tuned in to cell phone frequencies, enables agents to listen in on wireless calls.

  • DISCARDED PHONE BILLS, credit-card statements and computer hard drives can reveal a subject’s sensitive information.

  • AIRPLANES, unmanned aerial vehicles and satellites can monitor targets from above. The U.S. KH-11 spy satellite reportedly has a maximum image resolution of less than six inches; newer, still secret orbital surveillance systems may perform even better.

  • SMALL SPY DEVICES, equipped with surveillance gear, may soon fly or walk into sites of interest under remote control.

Note: This story was originally printed with the title, "Tools of the Spy Trade".

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Steven Ashley is a freelance science-technology writer and editor.

More by Steven Ashley
Scientific American Magazine Vol 299 Issue 3This article was published with the title “Digital Surveillance: Tools of the Spy Trade” in Scientific American Magazine Vol. 299 No. 3 ()
doi:10.1038/scientificamerican092008-3oMLdZoIKwomqToakbhxYb

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