Which of the following are security measures you should follow when using social media sites?

The choice to focus on is the guideline emphasizing the importance of not violating operations security by posting critical information. This is a crucial principle in maintaining operational integrity and safeguarding sensitive data, particularly within a military context. Operations security, or OPSEC, involves protecting unclassified information from being easily pieced together to infer or deduce sensitive aspects of operations or plans.

When individuals disclose critical information on social media, they could inadvertently provide adversaries with insights that compromise missions, personnel, or national security. This makes adhering to strict OPSEC practices vital for anyone involved in military operations. By avoiding the sharing of such information, service members help ensure the safety and effectiveness of their operations, thereby contributing to broader security measures.

Focusing on this aspect of social media usage underscores the necessity of being vigilant about sharing content and highlights the risks associated with seemingly innocuous posts. The other options, while they may touch on safety practices in various contexts, do not directly pertain to the critical nature of operational security and the implications that arise from failing to protect sensitive information shared online.