This is less Wal-Mart and more citizens being asked to turn on citizens. This is just another symptom of a greater attempt at government-level social control. It is a play taken out of the playbooks of many other expansive control focused governments. Separate the government from the people and then the people from each other. This is done through fear and threat of danger. It turns the citizens against one another out of suspicion and allows for enactment and implementation of power expanding policies.
Most people shrug little events off, dismissing it as a security precaution, harmless but unnecessary, or too minuscule to worry about. The fallacy in these perspectives lies in the individuals inability to see the big picture. The convergence of many many small "harmless" precautions. The structural framework of a greater system of control slowly piecing itself together around us. Building itself up like a cage, we don't mind the bars so much as long as we can still see light. By the time it is completed and the light is gone, it is too late.
That said, this should probably be in news/social . However, I enjoyed the thought provoking article.