The LINE messaging application is widely used by hundreds of millions of people globally, particularly across Asian markets, and incorporates standard security measures such as optional end-to-end message encryption via its "Letter Sealing" feature, two-step verification, and passcode locks. However, privacy advocates and security audits note potential concerns regarding data collection practices, metadata handling, targeted advertising integrations, and historical corporate data governance incidents. Users prioritizing strict privacy should manually enable Letter Sealing and adjust their account sharing preferences.