A telephone line or telephone circuit (or just line or circuit industrywide) is a single-user circuit on a telephone communication system. This is the physical wire or other signaling medium connecting the user's telephone apparatus to the telecommunications network, and usually also implies a single telephone number for billing purposes ...

Telephone tapping (also wire tapping or wiretapping in American English) is the monitoring of telephone and Internet-based conversations by a third party, often by covert means. The wire tap received its name because, historically, the monitoring connection was an actual electrical tap on the telephone line. ... Conversation on many early ...