Every once in a while it's good to be reminded of certain principles. In my first book I outlined three lessons I've learned while monitoring intruders. Sometimes threats in nature provide examples of these lessons.
Sguil developer Bamm Visscher pointed me to these images, which I have cropped and annotated for your network security monitoring enjoyment.
NSM Principle 1: Some intruders are smarter than you are.
NSM Principle 2: Intruders are unpredictable.
NSM Principle 3: Prevention eventually fails.
Hence, the need for monitoring, e.g., these photos!
Thank you to GeekBase for posting these -- I hope you prefer me not linking to the photos directly, thereby saving your bandwidth!