1. A telephony security system located within an enterprise, at one or more of said enterprise's locations, for monitoring and/or controlling calls, wherein said calls is understood to refer to an inbound call, an outbound call, or any combination thereof, between end-user stations within said enterprise and said end-user stations' respective circuits into a Public Switched Telephone Network (PSTN), said system comprising: one or more rules controlled by a system administrator, said one or more rules designating one or more actions, said one or more actions to include allowing or denying a call, said one or more actions to be performed based upon at least one attribute of said call; one or more line sensors, said one or more line sensors including: determining said at least one attribute of said call, and performing said one or more actions based upon said at least one attribute of said call; said one or more line sensors being constructed and arranged to not interrupt said call unless designated to do so in said one or more rules.