Which type of information should never be logged?

Logging is essential for application monitoring and troubleshooting, but it is crucial to ensure that sensitive information is protected. Personally Identifiable Information (PII) must never be logged because it consists of data that can identify individuals, such as names, addresses, social security numbers, and financial information. Logging this type of information poses significant security and privacy risks, as it could be exposed to unauthorized access and lead to identity theft or breaches of confidentiality. Organizations must comply with various regulations and standards that protect PII, such as GDPR and HIPAA, which impose strict guidelines on how such data is handled and secured.

In contrast, logging general application errors, debugging information for internal use, and log level configurations may be necessary for diagnosing issues and enhancing application performance. However, even with these types, care should be taken to ensure that sensitive data is not included.