Abstract: A building entrance protector unit (20) includes plurality of electrical connectors (86) providing electrical connections between wire pairs (104, 105) leading from telephone stations of subscribers in the building and wire pairs (57,58) from the local telephone networks serving the unit, these connections being interruptible by the subscribers for the purpose of plugging in their telephone sets to the network to test these sets. The connections are tamperproofed by a hasp mechanism (87) providing hasp leaves (130) respective to these connectors and each lockable in a first position impeding access to the corresponding connection by attachment of a padlock (170) to a hasp staple (150) projecting through that leaf. That locking may be overridden by a telephone network technician by a releasing from a held position of a common mounting (111) for all the hasp staples.