The Fourth Amendment Does Not Require “Demonstrative Action” to Protect Privacy
In a previous post, we discussed the test that the Supreme Court will likely use to resolve United States v. Carpenter, the major Fourth Amendment case that will be argued in the Supreme Court tomorrow. We responded to Orin Kerr’s argument that the Supreme Court should not consider people’s actual expectations of privacy in resolving Carpenter. In this post, we will examine Orin’s proposed alternative test and discuss the state of public knowledge about cell phone location tracking.
In Orin’s recent blog post, he discusses the connection between people’s knowledge of cell phone technology and their expectations of privacy in their cell phone’s location. Each of the appeals courts to examine the constitutionality of historical cell phone location tracking has based its decision in part on the extent of societal knowledge about cell phone technology. Controversially, most of these courts, including the Sixth Circuit in Carpenter, have concluded that cell phone users are generally aware that their cell phone companies are tracking their locations and storing records of their movements. This is a somewhat remarkable claim regarding public knowledge of an obscure and complex location tracking technology—and empirical surveys of cell phone users suggest that it is mistaken.
One of us has recently conducted a large-scale survey indicating that Americans are overwhelmingly not aware that their cell phone providers collect location information on them via their cell phones. Indeed, most people do not seem to be aware that their movements can be tracked using their cell phone signals. Accordingly, they do not knowingly disclose information about their movements to third parties. Nor do they consent to such disclosure, because one cannot consent to something unconsciously or unknowingly.
To his credit, Orin acknowledges the possibility that cell phone users are unaware of cell phone location tracking. He instead argues that users may eventually acquire this knowledge, in which case a decision in Carpenter’s favor on the basis of societal knowledge would eventually become “wrong.”
We have several responses to this. One is that a decision premised on an accurate assessment of societal knowledge at the time when Carpenter was tracked would not become “wrong” just because people eventually gain advanced knowledge of cell phone technology. Regardless of some hypothetical future defendant’s knowledge, it is fairly clear that Carpenter did not knowingly disclose his movements to a third party, and therefore did not forfeit his Fourth Amendment protections. Carpenter’s contemporaries (i.e., present-day Americans) generally shared his expectations.
Moreover, a large increase in knowledge of cell phone technology is unlikely in the foreseeable future. Public ignorance of even basic science is widespread and persistent. And, as we discussed in our previous post, social science studies indicate that Supreme Court cases have little impact on the perceptions or knowledge of the general public.
In any event, we consider Orin’s proposed alternative test for the Fourth Amendment’s scope to be untenable. Orin argues in Part IV of his amicus brief that the Court should ignore actual expectations of privacy and instead look to whether a citizen has “exhibited” an expectation of privacy by taking affirmative steps to prevent observation. Thus Orin contends that an expectation of privacy must be “demonstrated by an act” in order to receive constitutional protection.
Although Katz himself acted to protect his privacy by closing the telephone booth door before placing a call, a “demonstrative action” test would be a major departure from existing Fourth Amendment law, and an unwelcome one.
Fourth Amendment law is full of examples of courts finding Fourth Amendment protection for information accessible to others, even when the target has taken no demonstrative action to protect it. Kyllo engaged in no demonstrative action to prevent heat from escaping his house. Bond engaged in no demonstrative action to prevent the touching of his luggage. Five Justices agreed that tracking Jones’s location via GPS violated the Katz test, although Jones took no affirmative step to prevent the observation of his movements. Most people take no demonstrative action to prevent observation of their emails or the web sites they visit. Like Carpenter, the people in these examples reasonably expect privacy in their information and belongings. In fact, people who reasonably expect privacy in a given situation may be less likely to take action to protect their privacy, because such action is likely unnecessary. Requiring citizens to take affirmative steps to prevent observation of their information in order to claim Fourth Amendment protection would drastically depart from existing law and substantially shrink the scope of the Fourth Amendment.