Smith v. Maryland, 442 U.S. 735 (1979) (full-text).
Factual Background Edit
After she was robbed, Patricia McDonough began receiving "threatening and obscene phone calls from a man identifying himself as the robber." Police suspicion focused on Michael Lee Smith as the robber.
|“||The telephone company, at police request, installed a pen register at its central offices to record the numbers dialed from the telephone at [his] home. The police did not get a warrant or court order before having the pen register installed. The pen register revealed that on March 17 a call was placed from [his] home to McDonough's phone. On the basis of this and other evidence, the police obtained a warrant to search [Smith's] residence. The search revealed that a page in [his] phone book was turned down to the name and number of Patricia McDonough; the phone book was seized.||”|
Arrested and indicted, Smith moved to suppress "all fruits derived from the pen register" on the grounds that its installation and use was a warrantless search in violation of the Fourth Amendment. The trial court denied the motion and a divided Maryland Court of Appeals affirmed.
U.S. Supreme Court Proceedings Edit
The issue before the U.S. Supreme Court was "whether the installation and use of a pen register," which captures the numbers dialed on a telephone, "constitutes a 'search' within the meaning of the Fourth Amendment. The Court began by reviewing Katz v. United States and noting that the standard used to implement Katz is the two-pronged test Justice Harlan enunciated in his concurring opinion: (i) whether the individual has exhibited a subjective expectation of privacy in the thing, place or endeavor; and (ii) whether society is prepared to regard the individual's subjective expectation of privacy, if any, as reasonable.
The Court found that Smith met neither criterion:
|“|| Since the pen register was installed on telephone company property at the telephone company's central offices, petitioner . . . cannot claim that his "property" was invaded or that police intruded into a "constitutionally protected area.
Petitioner's claim . . . is that, notwithstanding the absence of a trespass, the State . . . infringed a "legitimate expectation of privacy" . . . . [A] pen register differs . . . from the listening device employed in Katz, for pen registers do not acquire the contents of communications. . . .
[P]etitioner's argument that its installation and use constituted a "search" necessarily rests upon a claim that he had a "legitimate expectation of privacy" regarding the numbers he dialed on his phone.
[W]e doubt that people in general entertain any actual expectation of privacy in the numbers they dial. All telephone users realize that they must "convey" phone numbers to the telephone company, since it is through telephone company switching equipment that their calls are completed. All subscribers realize . . . that the phone company has facilities for making permanent records of the numbers they dial, for they see a list of their long-distance (toll) calls on their monthly bills. . . . Telephone users, in sum, typically know that they must convey numerical information to the phone company; that the phone company has facilities for recording this information; and that the phone company does in fact record this information for a variety of legitimate business purposes. Although subjective expectations cannot be scientifically gauged, it is too much to believe that telephone subscribers, under these circumstances, harbor any general expectation that the numbers they dial will remain secret.
The Court also (i) rejected Smith's claim that he demonstrated a subjective expectation of privacy by making the calls from his home, and (ii) held that even if he could show such a subjective expectation, it is not one society would regard as reasonable:
|“||[E]ven if petitioner did harbor some subjective expectation that the phone numbers he dialed would remain private, this expectation is not "one that society is prepared to recognize as 'reasonable.'" This Court consistently has held that a person has no legitimate expectation of privacy in information he voluntarily turns over to third parties."||”|