Gr 9 Up-As the author notes, some of the "vulnerabilities that have made these widespread threats possible are the same technological advances that have made computers more useful and versatile." Personal ethics become part of the picture when the people who design and work with these systems have the ability to "wreak havoc on the Web." This text delves into the complex issues surrounding this topic. In chapter one, discussions of the development of viruses by hackers take readers from the computer department at MIT to the concept of shared computers and shared programs. Chapter two explains the early work of worms, their anatomy, and their evolution into something destructive. How different types of viruses such as the Trojan horse spread and grow as well as the parallel between biological disease and computer viruses further this discussion. Other chapters cover the motives of hackers, the extensive costs and impact of cyberattacks, and the efforts to provide a defense with antivirus software. The final chapter discusses the future of viruses and computer technology. Captioned black-and-white photos do little to entice readers, but diagrams, drawings, clever cartoons, a few charts, and fact boxes add some appeal.-Susan Shaver, Hemingford Public Schools, NE Copyright 2006 Reed Business Information.