Locking tabernacles?

Since the Middle Ages, when tabernacles were placed at arms reach, the custom of locking and fixing tabernacles began. Many hosts were either stolen and misused or eaten by rats, mice or other creatures for whom they were not intended. To protect the reserved Body of Christ, doors on tabernacles with locks have served to keep those out who do not have the same respect for the Blessed Sacrament as believers do. See General Instruction of the Roman Missal 2002, paragraph 314.