In ancient times it was widely believed that knowing the name of something gave you control over that person or thing . People would have secret names known only to themselves and to their closest friends and family, and a " use name " they would tell to the world at large . In this way they protected themselves from enemies who might use magic against them . Now it is the twenty-first century . Magic has returned to the world and there is a new culture of people who guard their names . They hide behind so-called " street names " to conceal their true identities from the law and to keep their real names out of the massive computer systems keeping track of nearly everyone in the world . Even the pirate users of the computer Matrix, the deckers, make use of false names to cover their transactions . In the age of technology, true names have become more important than ever .