## Facts

- The FBI investigated an illegal gambling operation and established probable cause that two telephones at a specified Manhattan address were used to further the activity.
- A federal district court authorized installation and use of pen registers on the two lines and ordered the New York Telephone Company to provide necessary information, facilities, and technical assistance, with compensation at prevailing rates.
- Pen registers record numbers dialed from a telephone but do not capture oral communications or indicate whether calls are completed.
- The telephone company provided some information but refused to furnish special leased lines needed for unobtrusive installation and moved to vacate the portion of the order requiring its assistance.
- The company argued that compelled assistance was permissible only under an order satisfying Title III of the Omnibus Crime Control and Safe Streets Act of 1968.
- The district court held Title III did not govern pen registers and concluded it could compel the company’s assistance under its authority, including the All Writs Act.
- The court of appeals agreed Title III did not apply and that the district court could authorize pen registers on probable cause, but ruled the district court abused its discretion by compelling the company’s assistance.
- The Supreme Court granted review to determine whether the district court could compel the company’s cooperation.

## Issues

1. Whether Title III’s regulation of orders authorizing interception of wire or oral communications applies to pen registers that record dialed numbers but not communication contents.
2. Whether a federal district court may, under the All Writs Act, compel a telephone company to provide technical assistance necessary to implement a lawful pen register order.

## Decision

- The Supreme Court reversed the court of appeals.
- Title III does not govern pen registers because they do not intercept the contents of communications as defined by the statute.
- The district court could authorize use of pen registers on probable cause.
- The All Writs Act authorized compelling the telephone company’s reasonable, compensated technical assistance because it was necessary to effectuate the court’s pen register order and the company was positioned to frustrate its execution.

## Legal Principles

- Title III applies to interception of the contents of wire or oral communications; pen registers that record only numbers dialed fall outside Title III.
- Federal courts may issue investigative orders on probable cause and may use ancillary authority to ensure execution of lawful orders.
- Under the All Writs Act, a court may direct non-parties to provide assistance that is necessary or appropriate to implement a valid order when the non-party is positioned to impede the order’s execution.
- Compelled third-party assistance is permissible where the order is limited in scope and duration, imposes no unreasonable burden, and provides compensation.

## Conclusion

The Court held that pen registers are not governed by Title III and that the All Writs Act permits a district court to require a telephone company to provide reasonable, compensated technical assistance needed to implement a lawful pen register order.


United States v. New York Telephone Co., 434 U.S. 159 (1977)