Answer: True
Step-by-step explanation:
The Intrusion Detection System (IDS) is used for the detection of malicious activities and thus is done by monitoring if the network communications and also the examination of systems logs.
When something looks suspicious of fishy, the Intrusion Detection System scans such thing out. When violations of policy occurs, the Intrusion Detection System is at alert to notice.
Therefore, the answer to the statement in the question is true.