Our reliance on computers and information-based technologies within DOD has greatly increased our potential for vulnerability if our information systems are attacked. DOD systems now receive numerous intrusion attempts daily and this trend appears to be increasing. It is paramount that DOD develops appropriate defensive courses of action to systematically and appropriately counter the threat of future cyber attacks. The main problem is distinguishing the type of intrusion or attack and developing the mechanisms to appropriately respond whether by law enforcement or military action. This book develops a spectrum of cyber conflict from hacking to information warfare which addresses who the adversary is, their intentions and how best to counter them. This spectrum of cyber conflict will consist of various forms of cyber attack such as hacking, hacktivism (a form of computer based civil disobedience), espionage, terrorism, and information warfare. The important issue in countering any form of cyber attack is to quickly discern the type of attack and adversary and respond appropriately. Currently, tracking down computer intrusions is a law enforcement function. The collection of information/evidence after the fact to trace the attacks back to the origin requires a robust and competent law enforcement community. The traditional war fighting military is prohibited from executing this mission domestically. If the US is a law enforcement theatre, now domestic law enforcement has a critical role in national security and national defense. This book will develop a spectrum of cyber-conflict and answer the question of when law enforcement or the military should respond to cyber attacks against US and DOD critical information systems.