The document discusses 5 common mistakes organizations make when deploying intrusion detection systems (IDS). 1. Not ensuring the IDS can see all network traffic by improperly planning its infrastructure placement. 2. Deploying an IDS but not reviewing the alerts it generates, diminishing its value as a detection system. 3. Deploying an IDS that generates alerts but having no response policy or understanding of normal vs anomalous activity. 4. Being overwhelmed by a high volume of alerts without properly tuning the IDS to the environment. 5. Not accepting the inherent limitations of signature-based IDS to detect new exploits without updated signatures.