In this chapter, we define and propose countermeasures for a category of computer security exploits which we call "cognitive hacking." Cognitive hacking refers to a computer or information system attack that relies on changing human users' perceptions and corresponding behaviors in order to be successful. This is in contrast to denial of service (DOS) and other kinds of well-known attacks that operate solely within the computer and network infrastructure. Examples are given of several cognitive hacking techniques, and a taxonomy for these types of attacks is developed. Legal, economic, and digital government implications are discussed.