Zone of Privacy

Zone of privacy refers to the areas or situations in which an individual has an expectation of privacy. This concept also provides an individual with some level of control over personal information. Zone of privacy examples include an individual’s right to feel secure in their person, home, or papers. To explore this concept, consider the following zone of privacy definition.

Definition of Zone of Privacy


  1. An area or aspect of an individual’s life for which the U.S. Constitution provides protection from government intrusion.

What is Zone of Privacy?

The U.S. Supreme Court first acknowledged that the Bill of Rights created a “zone of privacy” meaning in Griswold v Connecticut (1965). It found that, while the Constitution does not mention a right to privacy per se, several of the amendments have obscurities.

When grouped together, these references, or implied rights, create a private zone into which the government should not intrude. Though the court indicated that various zones exist, it used marriage and the home in its zone of privacy examples.

Griswold v Connecticut

In 1879, the state of Connecticut passed a law banning the use of contraception. Estelle Griswold and Dr. C. Lee Buxton opened a birth control clinic in New Haven in 1961.

A short time later, the state found Griswold and Buxton guilty of charges pertaining to the distribution of birth control. They appealed the court’s decision arguing the law clearly violated the privacy of married couples making it unconstitutional.

In 1965, the Supreme Court reviewed the case and reversed the lower court’s decision. It ruled that the ban on the use of contraceptives violated a right to marital privacy. The court explained that marriage created a zone of privacy which should remain free from government intrusion.

Reasonable Expectation of Privacy

The 4th Amendment protects people from warrantless searches in areas where they have a reasonable expectation of privacy. This is relevant to certain areas or aspects of life in which someone expects to remain private.

To determine the scope of protection, American courts apply the Reasonable Expectation of Privacy Test. Justice Harlan created this test with his concurring opinion in the U.S. Supreme Court case of Katz v. United States (1967).

Katz involved the police placing a wiretap on a public phone booth when attempting to stop a gambling ring. The court stated that people had an expectation of privacy in phone conversations, even calls made in public phone booths.

Reasonable Expectation of Privacy Test

According to the Reasonable Expectation of Privacy Test, sometimes called the Katz Test, 4th Amendment protections apply if:

  • An individual displays an actual or subjective expectation of privacy, and
  • Society recognizes this expectation as reasonable.

The clearest example of zone of privacy or reasonable expectation of privacy applies to a rented or owned residence. This protection does not apply to the short-term guests in the home, however.

Other instances where a reasonable expectation of privacy applies includes:

  • Phone booths
  • Public restrooms
  • Hotel rooms
  • Certain areas of a vehicle (dependent on state laws)

Along with physical places, people have a reasonable expectation of privacy with personal communications, such as letters and telephone calls. The same is true of any physical or electronic space that requires a key or password for access. Safety deposit boxes and lockers both qualify as examples of zone of privacy areas if the owner has a reasonable expectation of privacy.

By contrast, in places where a person does not have an expectation of privacy, police can search without a warrant. Some of these places and situations include:

  • Public sidewalks
  • Sporting venues
  • Roadways
  • Passengers in personal vehicles
  • Garbage left in the street
  • Any item on a person’s property that is easily visible from outside the property
  • Odors emanating from luggage

While the following items are considered to have no expectation of privacy, the keepers of the information will not turn the information over without a warrant or subpoena. These items can be subpoenaed with a warrant, however.

  • Electronic communications, such as e-mails and chat rooms
  • Bank account records

Constitutional Right to Privacy

The Constitution does not specifically make any mention to the right to privacy. However, the Supreme Court has noted that several amendments infer these rights. The court has even used its finding as the basis for decisions when reviewing various civil liberties cases. The following amendments imply a constitutional right to privacy:

  • The 1st Amendment guarantees the freedom to hold any religious belief and keep this belief private.
  • The 3rd Amendment protects the privacy of the home by prohibiting forcible housing of soldiers.
  • The 4th Amendment protects an individual’s personal and private space against unreasonable searches and seizures by the government.
  • The 5th Amendment protects against self-incrimination, which gives privacy to personal information.
  • The 9th Amendment justifies a broad reading of the Bill of Rights, by stating that the rights not listed in the Constitution belong to the people. In other words, privacy rights extend beyond the rights listed in the Constitution.
  • The 14th Amendment prohibits states from passing laws that might infringe on protections guaranteed in the first 13 amendments.

As technology continues to advance, the rules and rights involving private information also evolves. For instance, in 2012, the Supreme Court reviewed a case involving the constitutionality of warrantless searches of cell phones. It held that information on a cell phone has the same constitutional right to privacy as traditional forms of information.

Zone of Privacy Example Involving Thermal Imaging

In 1992, law enforcement suspected Danny Lee Kyllo of growing marijuana inside his home. Federal agents drove around his residence and used a thermal imaging device to scan it. Upon scanning the home, agents discovered that certain areas measured at a higher temperature than the rest.

They believed this change in temperature was a sign of high-intensity lamps used for growing marijuana. Based on the imaging, a federal judge issued a warrant to search the home, and officers found over 100 marijuana plants. Kyllo was subsequently indicted on federal drug charges.

Kyllo appealed on the grounds that results from a thermal-imaging scan constituted a search under the Fourth Amendment. The United States Court of Appeals for the Ninth Circuit upheld the ruling. Kyllo then appealed to the U.S. Supreme Court, which ruled in his favor.

The court explained that failure to obtain a warrant before using the device constituted a presumptively unreasonable search. The walls of a home create a zone of privacy where people have a reasonable expectation of privacy. Therefore, the government cannot conduct unreasonable searches, even if technology never enters the home. In this example of zone of privacy rights, the police violated a constitutional right to privacy.

Related Legal Terms and Issues

  • Bill of Rights – The first ten amendments to the U.S. Constitution.
  • Concurring Opinion – A written opinion by a judge which agrees with the overall decision made by a panel of judges, but which has different, or additional reasons for his decision.
  • Consent – To approve, permit, or agree.
  • Fifth Amendment – The Fifth Amendment protects people prosecution for the same crime twice, and states that the government cannot compel anybody to testify against themselves.
  • Jurisdiction – The legal authority to hear legal cases and make judgments; the geographical region of authority to enforce justice.
  • Scope – Relevant range of authority or practice, or range of control through a contract.
  • Statute – A written law passed by a legislature on the state or federal level.