If you know the enemy and know yourself, you need not fear the result of a hundred battles. If you know yourself but not the enemy, for every victory gained you will also suffer a defeat. If you know neither the enemy nor yourself, you will succumb in every battle." --Sun Tzu, The Art of War In order to defend a network, you first have to know and understand it. Deploying security sensors serves to not only block evil, but also as an intelligence collection system. Security and event logs provide an excellent opportunity to understand what is occurring on your network. Let's talk about sensor deployment and opportunities to find evil.