This is the cautionary chapter. Here Kurzweil talks a bit about what can go wrong, and more about the defensive technologies that can be implemented to make using these powerful tools safer.
One example he gives that is near and dear to my heart is comparing the defensive technology strategy of the IT software industry to that of the healthcare industry.
IT handles defensive technology as an integral part of the general industry development. It can do so because it is developing in a relatively free market environment. This environment produces diffuse and rapidly advancing defensive technology that is part of the generally rapidly advancing industry. Abuse happens, frequently, but the effects of it are small scale because the defensive technology is up-to-date.
Healthcare centralizes its defensive technology efforts and safety depends a lot on defensive regulations rather than defensive technology. In the US safety efforts are centralized in the FDA. This central planning slows progress and also makes it much more expensive for defensive technologies to keep pace with general advances because they are treated as distinct from the general advancement. This leads to more infrequent, but more catastrophic, abuse cycles.
He goes on to outline some possible disaster scenarios and categorize them, and outline some defensive technologies that can be envisioned to prevent them.