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 communication originator to block receipt of any individually identifying information without charge. Declares that such providers are not required to enable originators to block the receipt of such information or emergency assistance telephone lines of police and fire departments. Permits the use of pen registers and trap and trace devices on such emergency assistance lines.