An opacity baffle is disclosed that can be permanently secured to the back face of an electronic apparatus to cover ventilation openings or other openings that render the apparatus visually unsecure. The opacity baffle in one example comprises a grill and ventilation material that are secured together at their edges resulting in a rigid structure. The grill contains openings to promote ventilation within the apparatus, and the ventilation materials allows for air flow despite being visually opaque. One-way fasteners can be used to secure the baffle to the back face, which when inserted in place cannot be removed without evident tampering. The baffle and fasteners can be provided with the apparatus when sold or can be sold separately, allowing a particular customer to affix the baffle if needed to meet security requirements, or not if such security measures are unnecessary.