Theoretically copper wires should be very reliable- but carriers are moving large parts of their network to fiber or wireless or other vulnerable electronic technology. Such is life. Lets just hope that the clever big boys who are taking over and improving our lives in so many ways, don't make a little boo boo and relegate things back to the age of horse and cart. ;-)
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1