From the introduction:
Malls today are becoming increasingly dependent upon electronic devices. Automatic door locks, anti-theft alarms, motion sensors, self-mobile closed- circuit security cameras, even key-coded electronic locks on doors to staff-only areas... and all of it tied into a central computer sequestered somewhere in the bowels of the mall's sub-levels.
These systems are the computer geek's playground. Through the use of their consummate computing skills, these erstwhile operators can tap into the electronic pulse of the mall and manipulate it to suit their whims. There is no place a skilled computer geek cannot see, and no system a skilled computer geek cannot affect.