Telephone Privacy Act of 1991

Telephone Privacy Act of 1991 - Amends the Electronic Communications Privacy Act of 1986 to modify the exception to the prohibition on the use of pen registers or trap and trace devices to allow the use of caller identification devices where the provider of communication services enables the originator of a communication to a recipient to block caller identification on: (1) a per call basis without charge; (2) a per line basis in a State in which it is authorized by statute prior to the date of enactment of this Act; and (3) a per line basis without charge at the request of an originator that is a victim of domestic violence protected by court order, a victim's service program, or an organization providing safe haven for victims of domestic violence.

Declares that such providers are not required to enable originators to block call identification: (1) on the emergency assistance telephone line of a police or fire department or on 911 lines; (2) on calls within a customer's system; or (3) to a recipient of communication that uses call return service in connection with billing information associated with returned communications.

States that the prohibition applies in connection with communications to governmental entities, except for communications on emergency assistance telephone lines of police or fire departments or 911 emergency lines.

Lists conditions under which the use of information made available through an automatic number identification service is exempted from the prohibition on trap and trace devices. Includes within the exempted uses of such information uses concerning: (1) billing and collection, routing, screening, and completion of a call or services related to the originating subscriber's call; (2) reuse or sale after the recipient notifies the originator of the desire to reuse or sell the information and extends an option to limit or prohibit such action; (3) performance of a service, quality of network performance, or compliance with law or a court order; or (4) any lawful purpose if originators have the ability to block caller identification.

Permits civil actions by parties aggrieved by the failure of a provider to allow blocking of caller identification or by the illegal use of caller identification information by communication recipients. Prescribes civil and criminal penalties for violations of this Act.

Prohibits States from prohibiting providers from offering caller identification services.