What did the declassified documents reveal?

FBI Files: Ultrasonic Listening Devices / Wiretapping / Countermeasures. Released 2023-01-29. The Black Vault entry: https://www.theblackvault.com/documentarchive/ultrasonic-listening-devices-wiretapping/. Canonical PDF: https://documents.theblackvault.com/documents/fbifiles/1219492-0.pdf. This document was released in response to a Freedom of Information Act request submitted by John Greenewald, Jr. of The Black Vault. The request, filed under FOIPA Request No. 1219492-000, sought records related to ultrasonic listening devices and wiretapping. The FBI processed the request and provided a CD containing 1,057 pages of previously processed documents and a copy of the Explanation of Exemptions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epartment of Justice Federal Bureau of Investigation Washington, D.C. 20535 August 29, 2017 Devices exist which, by sending an electrical impulse of ultrasonic frequency through a telephone circuit by tapping, will permit remote surveillance of any office in which a telephone is located by utilizing the telephone microphone as a pick-up. Such eavesdropping may be accomplished without additional wires and is possible even though the handset is in a "hung-up" position. The FBI's response to the FOIA request includes an Explanation of Exemptions, which outlines the categories of records that are exempt from disclosure under the Freedom of Information Act. These exemptions include records related to national defense or foreign policy, personnel and medical files, and records compiled for law enforcement purposes. This is what the public record looks like at its most ordinary. storyflo.com.

Why was this case declassified?

This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process.

Case · DAILY-030

FBI Files: Ultrasonic Listening Devices / Wiretapping / Countermeasures

JUL 5 · 2026Narrated by daily-declassified-fbi-files-ultrasonic-listening-devices-wiretapping-counter3 minLast updated July 5, 2026

The short version

FBI Files: Ultrasonic Listening Devices / Wiretapping / Countermeasures. Released 2023-01-29. com/documentarchive/ultrasonic-listening-devices-wiretapping/. pdf. This document was released in response to a Freedom of Information Act request submitted by John Greenewald, Jr. of The Black Vault. The request, filed under FOIPA Request No.

Date: JUL 5 · 2026
Release: Declassified · U.S. public record (FOIA)

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Episode notes

FBI Files: Ultrasonic Listening Devices / Wiretapping / Countermeasures. Released 2023-01-29. The Black Vault entry: https://www.theblackvault.com/documentarchive/ultrasonic-listening-devices-wiretapping/. Canonical PDF: https://documents.theblackvault.com/documents/fbifiles/1219492-0.pdf. This…

Questions about this case

What was FBI Files: Ultrasonic Listening Devices / Wiretapping / Countermeasures about?: FBI Files: Ultrasonic Listening Devices / Wiretapping / Countermeasures. Released 2023-01-29. com/documentarchive/ultrasonic-listening-devices-wiretapping/. pdf. This document was released in response to a Freedom of Information Act request submitted by John Greenewald, Jr. of The Black Vault. The request, filed under FOIPA Request No.
Why was this case declassified?: This material entered the public record through the U.S. declassification and Freedom of Information Act (FOIA) process. Storyflo narrates it directly from the public release.

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