GOOD PRIMERS on tradecraft-methods and techniques -are available free at your local library. The hardware, however, costs dearly. You can never be completely impenetrable, but you can make yourself more trouble than you’re worth with a few well-placed purchases.
PARTY LINE EAVESDROP DETECTOR – One for each phone, $40 apiece.
BUGS – Simple high-gain mike and recorder, $60; tone-activated phone mike, $150 and up; peppercorns start at $1,200 each if you order a thousand.
POCKET NIGHT SCOPE- Litton M-841, $3,000 and up.
POCKET BUG/RECORDER DETECTOR – SRI’s TRD-800, $1,500.
FINGERPRINT-ACTIVATED FALSE ID DETECTOR – Comparator ID-1, $7,200.
PORTABLE VOICE STRESS ANALYZER – SRI’s ESM-4000, $2,300 without accessories.
BOMB DETECTOR – Intex J-7, $6,800.
ACOUSTIC-WAVE GENERATOR, TRANSDUCER AND INDUCTOR – SRI’s ANG-150, $1,200.
PORTABLE PHONE SCRAMBLER – SRI’s PPS-225, $800/pair.
SURGICAL GLOVES – Micro-touch, about $12 a box of 50 pairs.
LOCK PICK SET – $50, top of the line.
MINIATURE CAMERA – Minox C, $250 if you can find one.
COMPUTER TAP KIT – AM/FM/cassette recorder, TI 753 terminal, about $1,000.
And if you don’t have that kind of money, you can steal the designs and make your own.