# Application Telemetry and Privacy Controls One-sentence definition: Instrument apps to observe health and security while protecting user privacy. ## Key Facts - Emit metrics, traces, and logs with correlation IDs; sample to control cost. - Mask tokens/PII; use data classification to decide what to log. - Export over TLS; sign or authenticate to collectors; time-synced. - Provide opt-outs where required; document retention and access controls. - **Verify:** check official (ISC)² CBK and current exam outline. ## Exam Relevance - Spot privacy leaks in telemetry and missing masking. **Mnemonic:** “**See behavior, not identities**.” ## Mini Scenario Q: Trace captures full PAN—violation/fix? A: Sensitive data exposure; mask or avoid logging; validate exporters. ## Revision Checklist - Three telemetry types. - Masking rule. - Retention/access note. ## Related [[Secure Error Handling and Logging for Apps]] · [[Logging Strategy and SIEM Use Cases]] · [[Privacy by Design and Data Classification in SDLC]] · [[Security Dashboards and Executive Metrics]] · [[Domain 8 - Index]]