Wiretapping is the oldest form of modern surveillance, with new technology it’s more powerful than ever.

Wiretapping is using a device to listen in on a person’s phone calls. Pen registers are a similar technology used to collect a record of who a person calls, when, and for how long, without recording the content of the calls. Early uses of this technology shaped privacy law in the U.S.

Today wiretaps and pen registers are performed by phone companies without installing physical surveillance devices. Wiretaps were heavily abused by U.S. intelligence agencies that engaged in widespread warrantless wiretaps in the years after the September 11th attacks.

Despite the warrant requirement for law enforcement to engage in a wiretap, privacy issues still exist. A wiretap doesn’t just spy on the person tapped, it also spies on everyone who calls them. The U.S. government’s requirement of telecommunication companies to make wiretapping easier, makes communication less secure and increases privacy risks for everyone else. Limiting the use of wiretaps to warrants supported by good cause and protecting end-to-end encrypted communications is vital to protecting privacy.

Wiretaps: The Original Surveillance Technology

Wiretaps Shaped Privacy Law

An early wiretap performed without a warrant was the origin of the landmark privacy case Olmstead v. United States, 277 U.S. 438 (1928). Although the majority ruled that a warrantless wiretap did not violate the 4th Amendment, Justice Louis Brandeis’s dissent in that case laid out many of the fundamental principles of modern 4th Amendment jurisprudence.

Justice Brandeis’ dissent was an important factor in Katz v. United States, 389 U.S. 347 (1967). The court in Katz ruled that installing a listening device on a telephone booth was a search under the 4thAmendment, effectively overturning Olmstead and setting up the “reasonable expectation of privacy” analysis. Brandeis’s dissent was also cited in Carpenter v. United States, 585 U.S. __ (2018), establishing a right to privacy in location data obtained from cell phones.

Communications Assistance for Law Enforcement Act (CALEA)

The Communications Assistance for Law Enforcement Act (CALEA) was passed by Congress in 1994. The act required telephone companies to make it easier for law enforcement to wiretap telephone calls. In 2005, the Federal Communications Commission broaden CALEA to include Internet service providers (ISPs) and VoIP services. EPIC opposed the CALEA and its expansion by the FCC.

Wiretaps Were Widely Abused After 9/11

In the years after the September 11th attacks the National Security Agency engaged in a years-long program of wiretapping without warrants in violation of the 4th Amendment and Foreign Intelligence Surveillance Act as part of the agency’s “Terrorist Surveillance Program”. After substantial public outcry and adverse court rulings the program was ended in 2007 and replaced with the NSA’s current mass surveillance program, PRISM.

Wiretap Technology is More Powerful Than Ever

Today wiretapping is done electronically by telephone companies that receive a warrant. The digital version of a pen register is a substantial improvement. Under the NSA’s PRISM program and other intelligence surveillance programs, wireless providers and internet service providers willingly turn over massive volumes of call and internet use data without a warrant. Revealed by Edward Snowden, PRISM allows the NSA to intercept and analyze the majority of electronic communications worldwide, without meaningful due process protections.

EPIC’s Work

EPIC advocates for both courts and Congress to restrict the use of wiretaps and preserve privacy over the phone. EPIC opposes any measure to make wiretaps easier that compromises the security and privacy of communications. EPIC attorneys regularly investigate the use of wiretaps by intelligence agencies.

Recent Documents on Wiretapping

  • Amicus Briefs

    Facebook v. New Jersey

    New Jersey Supreme Court

  • FOIA Cases

    EPIC v. DOJ (CSLI Section 2703(d) Orders)

    US District Court for the District of Columbia

    EPIC is seeking the public release of information detailing the Department of Justice's collection of cell site location information through S 2703(d) court orders.

  • Amicus Briefs

    Smith v. LoanMe

    California Supreme Court

    Whether the California Invasion of Privacy Act prohibits parties to a call from recording a call without the consent of all parties

  • FOIA Cases

    EPIC v. DOJ – Pen Register Reports

    US District Court for the District of Columbia

    Seeking the reports that detail the NSA's collection of call record information from US companies, which the Justice Department has routinely prepared for Congress but never made available to the public.

  • FOIA Cases


    US District Court for the District of Columbia

    Seeking the legal analyses from the Office of Legal Counsel concerning the NSA PRISM program.

  • Amicus Briefs

    SEC v. Galleon Management

    US Court of Appeals for the Second Circuit

    Whether an individual is required to turn over more than 18,000 wiretapped conversations acquired by the government in a criminal case when the Securities and Exchange Commission (SEC) compels the disclosure of such material in a separate but related civil case

  • FOIA Cases

    EPIC v. DOJ – Warrantless Wiretapping Program

    US District Court for the District of Columbia

    Seeking the legal memos justifying the warrantless wiretapping program of the Bush Administration

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