The Naval Discipline Act of 2550 was placed thereby the Unified Earth Government. It governs discipline and criminal penalties in the UNSC Navy, including the Office of Naval Intelligence. Originally created by the Defense Committee to build off the Official Secrets Act, this act allows the UNSC to place criminals and defectors on the life sentence or dealth penalty. Espionage, defection, desertion, and committing acts likely to aid the enemy are violations against the Naval Discipline Act which are treated with heavy punishment by the UNSC.
Acts like these get passed exclusively under extreme circumstances. Humanity was on the brink of extinction, and with the Cole Protocol in place, keeping secrets was the UNSC's top priority in delaying the Covenant onslaught. Thus, the Official Secrets Act of 2550 was passed. Enforcing these secrets on the Navy was the purpose of the Naval Discipline Act.