Back in the days of phreaking, this was called a 'Cheese Box' and was used to great effect by calling two locations of any chain. From what I recall, a report i

Back in the days of phreaking, this was called a 'Cheese Box' and was used to great effect by calling two locations of any chain. From what I recall, a report in Phrack called two 711 employees who started yelling at each other 'NO, THIS IS 711, WHO IS THIS‽'