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Undergound. Go to Table of Contents.

   equipment at any time. The ultimate reason to hate Telecom.


   There was such hatred of Telecom that people in the computer

   underground routinely discussed ways of sabotaging the carrier. Some

   people talked of sending 240 volts of electricity down the telephone

   line--an act which would blow up bits of the telephone exchange along

   with any line technicians who happened to be working on the cable at

   the time. Telecom had protective fuses which stopped electrical surges

   on the line, but BBS hackers had reportedly developed circuit plans

   which would allow high-frequency voltages to bypass them. Other

   members of the underground considered what sweet justice it would be

   to set fire to all the cables outside a particular Telecom exchange

   which had an easily accessible cable entrance duct.


   It was against this backdrop that the underground began to shift into

   phreaking. Phreaking is loosely defined as hacking the telephone

   system. It is a very loose definition. Some people believe phreaking

   includes stealing a credit card number and using it to make a

   long-distance call for free. Purists shun this definition. To them,

   using a stolen credit card is not phreaking, it is carding. They argue

   that phreaking demands a reasonable level of technical skill and

   involves manipulation of a telephone exchange. This manipulation may

   manifest itself as using computers or electrical circuits to generate

   special tones or modify the voltage of a phone line. The manipulation

   changes how the telephone exchange views a particular telephone

   line. The result: a free and hopefully untraceable call. The purist

   hacker sees phreaking more as a way of eluding telephone traces than of

   calling his or her friends around the world for free.


   The first transition into phreaking and eventually carding happened

   over a period of about six months in 1988. Early hackers on PI and Zen

   relied primarily on dial-outs, like those at Melbourne University or

   Telecom's Clayton office, to bounce around international computer

   sites. They also used X.25 dial-outs in other countries--the US,

   Sweden and Germany--to make another leap in their international



   Gradually, the people running these dial-out lines wised up. Dial-outs

   started drying up. Passwords were changed. Facilities were cancelled.

   But the hackers didn't want to give up access to overseas systems.

   They'd had their first taste of international calling and they wanted

   more. There was a big shiny electronic world to explore out there.

   They began trying different methods of getting where they wanted to

   go. And so the Melbourne underground moved into phreaking.


   Phreakers swarmed to PABXes like bees to honey. A PABX, a private

   automatic branch exchange, works like a mini-Telecom telephone

   exchange. Using a PABX, the employee of a large company could dial

   another employee in-house without incurring the cost of a local

   telephone call. If the employee was, for example, staying in a hotel

   out of town, the company might ask him to make all his calls through

   the company's PABX to avoid paying extortionate hotel long-distance

   rates. If the employee was in Brisbane on business, he could dial a

   Brisbane number which might route him via the company's PABX to

   Sydney. From there, he might dial out to Rome or London, and the

   charge would be billed directly to the company. What worked for an

   employee also worked for a phreaker.


   A phreaker dialling into the PABX would generally need to either know

   or guess the password allowing him to dial out again. Often, the