Firewall (Person of Interest)

In the CBS television series Person of Interest, "Firewall" refers to a specific type of mission undertaken by the team consisting of John Reese, Harold Finch, Samantha Shaw, and sometimes Sameen Shaw. A Firewall mission is initiated when The Machine, an artificial superintelligence that predicts acts of terror, identifies an imminent threat that involves either a person of interest (POI) number or the Machine itself.

Firewall missions are considered high-priority and are usually more dangerous than typical cases involving the "relevant" numbers (those directly connected to crimes of violence). These missions often involve protecting the Machine's integrity and operational capabilities from detection, manipulation, or destruction by external forces. They also frequently deal with threats posed by rival AIs such as Samaritan or its operatives.

The stakes in Firewall missions are significantly higher, as failure could have devastating consequences, potentially leading to the exposure of the Machine's existence or the compromise of national security. Due to the sensitive nature of these cases, the team often operates with increased secrecy and employs more extreme measures to achieve their objectives. Unlike regular number cases where the team tries to prevent violence by influencing individuals, Firewall missions often involve direct confrontation with organizations or entities actively working against the Machine and its goals.