The Fourth Amendment to the US Constitution provides essential protection against unreasonable searches and seizures.

The third-party doctrine is an exception to the 4th Amendment when people lack a reasonable expectation of privacy.

Yet, this safeguard is not unlimited. The third-party doctrine, a legal principle established by court rulings, creates an exception to this rule because individuals generally do not have a reasonable expectation of privacy in information they have shared publicly.

In the digital age, the third-party doctrine could significantly impact our privacy, especially due to technologies that continuously monitor our actions.

According to the Fourth Amendment, the home is a sanctuary where individuals can retreat and be protected from unreasonable government searches and seizures. It receives the highest level of legal protection.

If a home incorporates artificial intelligence, any data shared with third parties, such as Amazon, is unlikely to be considered private.

No Reasonable Expectation of Privacy

The third-party doctrine asserts that there is no reasonable expectation of privacy for voluntarily shared information.

The Fourth Amendment safeguards individuals' rights to security in their persons, homes, documents, and possessions from unreasonable searches and seizures. Recently, however, the interpretation of this Amendment has evolved.

In today's society, we send our DNA samples by mail to explore our family history, rely on Alexa microphones at home for convenience, and store documents in the Cloud and on Dropbox.

Although voluntary exposure is fundamental to the third-party doctrine, technological advancements have altered privacy protections. 

Defining The Fourth Amendment  

The Fourth Amendment safeguards U.S. residents against unlawful searches and seizures of their "houses, papers, and effects."

This requires law enforcement and federal agents to secure a warrant supported by "probable cause" before performing a search. Probable cause is a reasonable belief, grounded in factual evidence, that a crime has occurred.

The Fourth Amendment aims to protect citizens' privacy expectations and allow them to live without fear of unwarranted or arbitrary government intrusions.

The Fourth Amendment of the United States Constitution states that people's right to be secure in their persons, homes, papers, and belongings shall not be infringed by unreasonable searches and seizures.

It also specifies that warrants can be issued only on probable cause, supported by oath or affirmation, and must specify the location and the items or persons to be seized.

Over time, court rulings have established exceptions to the Fourth Amendment, including the third-party doctrine. This principle states that people forfeit their privacy expectations when they voluntarily share information with third parties.

Consequently, law enforcement can often access data you have shared with others without a warrant.

Katz v. United States (1967)

Katz v. United States (1967), decided by the Supreme Court, significantly redefined the scope of the Fourth Amendment's protections against unreasonable searches and seizures.

The case involved Charles Katz, who was accused of transmitting betting information via telephone across state borders. Katz used a public phone booth for his illegal activities, unaware that the FBI had installed an electronic eavesdropping device outside the booth to intercept his conversations.

The Supreme Court determined that the government's actions violated the Fourth Amendment, holding that Katz had a 'reasonable expectation of privacy' even in a public phone booth, rendering the warrantless eavesdropping an unlawful search.

Nonetheless, the Court also noted: 'What a person knowingly exposes to the public, even in his own home or office, is not protected by the Fourth Amendment.'

This statement laid the groundwork for the development of the third-party doctrine in later court cases, including United States v. Miller (1976) and Smith v. Maryland (1979).

In Miller, the Court ruled that the Fourth Amendment does not protect bank records because the information was voluntarily provided to a third party, the bank.

Smith extended this logic to phone numbers dialed, arguing that the caller lacked a reasonable expectation of privacy because those numbers were voluntarily shared with the telephone company.

Carpenter v. United States (2018)

The rise of digital technologies and the internet has expanded the application of the third-party doctrine. Nowadays, we share extensive data with third parties—ranging from search queries on Google to location information from smartphones.

A notable example is Amazon's Alexa, a virtual assistant that reacts to voice commands and serves as the core of many "smart homes."

Alexa detects a "wake word" to activate and process commands, but it records all interactions following the wake word. This raises important privacy issues and has sparked debate over whether law enforcement can access your Alexa data without a warrant under the third-party doctrine.

Recent court decisions seem to be trending toward limiting the reach of the third-party doctrine-mainly on the premise that the voluntary exposure of personal information is becoming a thing of the past and that divulging such data is no longer a meaningful choice.

The 2018 Supreme Court case Carpenter v. United States marked a major shift in how the third-party doctrine is understood in light of modern technology. The case involved Timothy Carpenter, whose cell-site location data was collected by the FBI without a warrant, resulting in his robbery conviction.

The Supreme Court decided that obtaining these records constitutes a search under the Fourth Amendment, which mandates a warrant supported by probable cause.

The ruling acknowledged the specific privacy issues of the digital age, especially the widespread use of long-term location tracking and the unavoidable digital footprints left by individuals.

Safeguarding Your Privacy and Rights

The third-party doctrine holds that the law doesn't protect information shared with a trusted accomplice if that accomplice betrays that trust.

However, the Court has refused to apply this doctrine to data collected by cell phones, acknowledging their large storage capacity and crucial role in modern life.

Because of this, the court considered the doctrine of voluntary assumption of risk inapplicable in that situation. Grasping these legal principles is essential for anyone facing criminal charges.

If you think the evidence was obtained through a warrantless search, understanding the Fourth Amendment and the third-party doctrine can help you challenge its use in court.

A skilled federal criminal defense attorney can assess your case and identify the best ways to safeguard your Fourth Amendment rights. You can reach out to our law firm for a case review by phone or through the contact form. Eisner Gorin LLP is located in Los Angeles, California.