OPSEC

Operational security as a discipline, identifying what leaks, separating identities, and resisting the attacks aimed at humans instead of machines.

Operational security is the discipline of not defeating your own tools. Encryption, Tor, and hardened devices fail open when the person using them reuses a username, mentions their hometown, or answers a well-crafted phone call. Historically, that is how nearly everyone gets caught. The Darwin Awards section is the case-study companion to this one.

OPSEC is also the most transferable skill on this site: the same thinking protects an activist, a business negotiation, and an ordinary person leaving an abusive relationship.

OPSEC Fundamentals The five-step OPSEC process, the principle that consistency beats intensity, and the failure patterns that actually unmask people.
Identity Compartmentalization Keeping contexts separate so one exposure doesn't cascade, from two browsers to fully separated identities, and the linkage channels that defeat them.
Social Engineering Attacks aimed at people instead of systems, pretexting, phishing, and the verification habits that defeat them.