Data loss prevention (DLP) systems monitor data in use, in motion, and at rest to identify and block unauthorized disclosure of confidential information including personal data, intellectual property, and regulated data. DLP combines content inspection, contextual analysis, and policy enforcement across email, cloud storage, endpoints, and networks. An aerospace contractor implements DLP monitoring 8,500 endpoints and network traffic, blocking 2,300 monthly attempts to email technical drawings externally, encrypt sensitive files to unauthorized cloud storage, or copy source code to USB drives, with policy violations triggering security investigations.