The Couchbase Eventing service allows developers to create functions that can detect changes in documents as they happen, enabling real-time monitoring of sensitive information such as social security numbers. This feature is available as part of Couchbase Server 5.5 and can be used to trigger notifications when sensitive data is detected. To use the Eventing service, a developer must set up two buckets and configure a whitelist for outgoing requests. A function can then be created using N1QL queries to detect changes in documents and send notifications to an API endpoint. In this example, the function checks if a document contains a social security number and sends a notification if it does. The Eventing service is intended for development purposes only and should not be used in production environments.