If they were pulled up so they appeared straight they would snap under the tension unless they were supported by a steel cable. But then that would cost more to maintain the lines and cost you more money for your phone bill.then I guess they would have to have stronger poles to be able to hold the wires taut.probably metal poles instead of wood poles this in turn would cost even more money unless the poles were indestructible so they would never need repair or replacement in the future.