ities
in sophisticated phone services.

Cellular phones are especially vulnerable; their chips can be
re-programmed to present a false caller ID and avoid billing. Doing so
also avoids police tapping, making cellular-phone abuse a favorite
among drug-dealers. "Call-sell operations" using pirate cellular
phones can, and have, been run right out of the backs of cars, which
move from "cell" to "cell" in the local phone system, retailing stolen
long-distance service, like some kind of demented electronic version of
the neighborhood ice-cream truck.

Private branch-exchange phone systems in large corporations can be
penetrated; phreaks dial-up a local company, enter its internal
phone-system, hack it, then use the company's own PBX system to dial
back out over the public network, causing the company to be stuck with
the resulting long-distance bill. This technique is known as
"diverting." "Diverting" can be very costly, especially because phreaks
tend to travel in packs and never stop talking. Perhaps the worst
by-product of this "PBX fraud" is that victim companies and telcos have
sued one another over the financial responsibility for the stolen
calls, thus enriching not only shabby phreaks but well-paid lawyers.

"Voice-mail systems" can also be abused; phreaks can seize their own
sections of these sophisticated electronic answering machines, and use
them for trading codes or knowledge of illegal techniques. Voice-mail
abuse does not hurt the company directly, but finding supposedly empty
slots in your company's answering machine all crammed with phreaks
eagerly chattering and hey-duding one another in impenetrable jargon
can cause sensations of almost mystical repulsion and dread.

Worse yet, phreaks have sometimes been known to react truculently to
attempts to "clean up" the voice-mail system. Rather than humbly
acquiescing to being thrown out of their playground, they may very well
call up the company officials at work (or at home) and loudly demand
free voice-mail addresses of their very own. Such bullying is taken
very seriously by spooked victims.

Acts of phreak revenge against straight people are rare, but voice-mail
systems are especially tempting and vulnerable, and an infestation of
angry phreaks in one's voice-mail system is no joke. They can erase
legitimate messages; or spy on private messages; or harass users with
recorded taunts and obscenities. They've even been known to seize
control of vo