Changes in technology are putting pressure on the constitutional rules that determine when law enforcement officers need a search warrant to gather information. One rule that seems particularly strained is the “third party doctrine,” which maintains that the police do not need a warrant to collect information that an individual has voluntarily turned over to a third party. Some judges (and at least one Supreme Court justice) have indicated their willingness to rethink the third party doctrine. In this post, I argue that judges and scholars who want to reject (or limit the scope of) the third party doctrine might find support for their arguments in the cases governing workplace searches.

Background: The Third Party Doctrine

In general, the police do not need a warrant to gather information unless: (1) they trespass upon private property in order to gather the information; or (2) they intrude upon an individual’s reasonable expectation of privacy in the process of gathering the information. Under the third party doctrine, an individual cannot have a reasonable expectation of privacy in information that she voluntarily reveals to a third party. As a result, if the third party gives the information to the police, the police can accept the information without obtaining a warrant.

In the 1970s, the Supreme Court stretched the third party doctrine to new extremes. In a case called United States v. Miller, the Court held that individuals cannot have a reasonable expectation of privacy in their bank records, because they “voluntarily” reveal the information contained in those records to the bank. The Court explained that, even if an individual reveals the information for a limited (business) purpose, and even if the bank promises that the information will be kept confidential, the individual runs the risk that the bank will turn the information over to the government.

Three years later, in Smith v. Maryland, the Supreme Court held that individuals cannot have a reasonable expectation of privacy in the phone numbers they dial because they know that the telephone company (a third party) might see those numbers. In Smith, the police asked the phone company to record the phone numbers that a suspect dialed, and the phone company agreed. Crucially, the Court said that it did not matter whether the phone company would have recorded the suspect’s numbers in the ordinary course of carrying out its business. As long as the company could have record the numbers for a business purpose, the company was free to record the numbers for the purpose of assisting the police.

Miller, Smith, and their progeny rely on two particularly troublesome ideas. The first is that an individual can never have a reasonable expectation that a business will use her information for limited purposes, or share her information with a limited set of people. As Justice Sotomayor recently observed, it is troubling to think that an internet service provider could show the government (or anyone else) a complete list of websites that a customer has visited. Nevertheless, under Miller and Smith, this practice would be constitutionally permissible.

Second, Miller and Smith suggest that individuals can make a “voluntary” choice to use something as important as a bank or a telephone. In the words of Justice Marshall, a telephone is a “personal or professional necessity” for many people. If someone has “no realistic alternative” to using a phone, it is simply unfair to say that she “voluntarily” reveals the numbers she dials to the phone company.  

Thankfully, some employment cases seem to provide precedent that the Supreme Court could use to reject—or at least limit the scope of—these two troubling ideas.    

Cases Governing Workplace Searches

Two employment cases could be read to reject the troubling ideas embodied in Miller and Smith.

In O’Connor v. Ortega, the Supreme Court considered whether a government employer may search an employee’s office without a warrant. A plurality of the Court concluded that some government employees have a reasonable expectation of privacy in their workspaces. This expectation of privacy, however, is not always absolute: given the “operational realities of the workplace,” some government employees should expect that their supervisors will access their offices, desks, or file cabinets.

According to the logic of Smith v. Maryland, if an employer can access someone’s workspace to accomplish a business goal, the employer should be able to access—or permit the police to access—the workspace to conduct a criminal investigation. The O’Connor plurality, however, rejected this idea. Even when an employee knows that her co-workers might access her workspace, the plurality explained, she can still have a “reasonable expectation of privacy against intrusions by police.” As a result, an employee might reasonably expect that some intrusions into her workspace will be carried out “by a supervisor rather than a law enforcement official.”

Thus, O’Connor suggests that when public employees allow their employer (a third party of sorts) to access information kept in their workspace, they may have a reasonable expectation that the employer will use the information for limited (business) purposes, or share the information with a limited set of people.

In another key case, Marshall v. Barlow’s Inc., the Supreme Court rejected the idea that someone can give “voluntary” consent to a search when she is presented with a choice between submitting to the search and giving up a business necessity. In Marshall, the Court held that, in general, OSHA employees need a warrant to enter the non-public areas of a business establishment and conduct a safety inspection. The Court acknowledged, however, that some businesses are part of such “closely regulated industries” that their proprietors should expect frequent administrative inspections. Anyone who chooses to establish a business in a closely regulated industry is presumed to consent to these inspections. Consequently, government administrators do not need a warrant to inspect “pervasively regulated businesses.”

Crucially, the Marshall Court refused to hold that all business operating in interstate commerce are part of a closely regulated industry. As the Court explained, only “the most fictional sense of voluntary consent to later searches [can] be found in the single fact that one conducts a business affecting interstate commerce; under current practice and law, few businesses can be conducted without having some effect on interstate commerce.” In other words, the Court acknowledged that, for most businesses, the choice between submitting to administrative searches and operating outside of interstate commerce is no real choice at all: most business need to operate in interstate commerce in order to survive. Thus, the Court breathed life back into Justice Marshall’s statement that people cannot voluntarily consent to searches when access to a “professional necessity” is at stake.


< p>While O’Connor and Marshall do not come close to overruling the third party doctrine, they do express some principles that counterbalance the principles underlying Miller and Smith. Thus, O’Connor and Marshall support the idea that the logic motivating the third party doctrine has its limits.