Final answer:
Piggybacking in the context of Delta Security procedures refers to an unauthorized person gaining access to a secure area by following an authorized individual without being detected or challenged.
Step-by-step explanation:
When discussing Delta Security procedures, "Piggybacking" refers to allowing someone to enter a secured area without proper authorization. This can happen when an authorized person opens a door with their access credentials and an unauthorized person follows them in without being noticed. It is considered a security risk because it bypasses the established security protocols designed to limit access to sensitive areas. Preventing piggybacking is important for maintaining the integrity of secure environments.