Emerging technologies and their possible implications for ethics, security, and even human existence have increasingly gained ground in the past two decades. Some innovations have resulted in obvious security and existential threats: a world with nuclear arms, for example. The potential of other technological shifts, however, has been more mixed. Biotechnologies, genetic engineering, and stems cells have given rise to controversial debates in which advocacy groups on both sides have convincingly put forward pros and cons. The Internet has revolutionized everything from markets to family communication in ways both beneficial and harmful.