Storing sensitive information in cleartext is a fundamental security failure because it removes the primary barrier protecting data at rest. Whether the exposure happens via a database breach, log file leakage, or insecure backups, attackers can immediately read and misuse the information without needing to crack encryption. This flaw directly violates the core security principle of defense in depth and is often the root cause of massive data breaches. To prevent this, developers must ensure that all sensitive data is encrypted before being written to any storage medium, using strong, standard cryptographic libraries. Additionally, consider minimizing data collection, implementing robust key management, and regularly auditing storage locations—like logs, debug files, and analytics caches—to ensure no sensitive data is accidentally persisted in plain text.