... and you're not following developments in Fourth Amendment law.

Jeffrey Toobin is the latest to claim that Smith v. Maryland settles the Fourth Amendment issues around the National Security Agency's acquisition of data about every call made in the United States. He even links to the text of the decision in a recent blog post.

The majority opinion in Smith did say that people don't have a reasonable expectation of privacy in phone records, but that rationale is weak, and the facts of Smith are inapposite to the present controversy. I think that's easily gathered from reading the case with awareness of legal currents.

Here's what happened in Smith:

On March 5, 1976, in Baltimore, Md., Patricia McDonough was robbed. She gave the police a description of the robber and of a 1975 Monte Carlo automobile she had observed near the scene of the crime. After the robbery, McDonough began receiving threatening and obscene phone calls from a man identifying himself as the robber. On one occasion, the caller asked that she step out on her front porch; she did so, and saw the 1975 Monte Carlo she had earlier described to police moving slowly past her home. On March 16, police spotted a man who met McDonough's description driving a 1975 Monte Carlo in her neighborhood. By tracing the license plate number, police learned that the car was registered in the name of petitioner, Michael Lee Smith.

The next day, the telephone company, at police request, installed a pen register at its central offices to record the numbers dialed from the telephone at petitioner's home. The police did not get a warrant or court order before having the pen register installed. The register revealed that on March 17 a call was placed from petitioner's home to McDonough's phone. On the basis of this and other evidence, the police obtained a warrant to search petitioner's residence. The search revealed that a page in petitioner's phone book was turned down to the name and number of Patricia McDonough; the phone book was seized. Petitioner was arrested, and a six-man lineup was held on March 19. McDonough identified petitioner as the man who had robbed her. (citations omitted)

It is not possible to argue honestly that the facts of Smith are anything like the NSA's bulk data collection. The police had weighty evidence implicating one man. The telephone company voluntarily applied a pen register, collecting analog information about the use of one phone line by that one suspect. I can't think of a factual situation that could be at a further extreme than NSA's telephone calling surveillance program.

Apologists for NSA spying have to rest their argument entirely on the Smith Court's conclusion that there is no "expectation of privacy" in phone dialing information. But this is an unsafe resting place for at least two reasons.

First, the Court decided the Smith case wrongly, misapplying the "reasonable expectation of privacy" test, as courts often do. Randy Barnett and I pointed this out in our recent brief to the Supreme Court:

Justice Blackmun inaccurately applied ["reasonable expectation"] doctrine. The question whether a person has an actual (subjective) expectation of privacy is a question of fact, but the Court treated it as an objective question, denying the possibility of such an expectation. (“[I]t is too much to believe that telephone subscribers, under these circumstances, harbor any general expectation that the numbers they dial will remain secret.”) Having misapplied the subjective part of the Katz test, the Court appears also to have botched the objective part. Justice Blackmun marshaled arguments for the position that an expectation of privacy is unreasonable, but made no comparing or contrasting mention of counterarguments. Most likely, he treated the objective part of the Katz test subjectively, universalizing his own opinion as though it were the one true opinion on privacy around telephone dialing information. (citations omitted)

But more importantly, the Supreme Court is moving away from the "reasonable expectation of privacy" test entirely. In major Fourth Amendment decisions like Kyllo (2001) and Jones (2012), the Court did not use the "reasonable expectation of privacy" test to examine scanning of a home with a thermal imager and tracking of a vehicle with a GPS device. (Both require a warrant.) In Jardines, decided last term, the Court did not use the "reasonable expectation of privacy" test in finding that walking a drug-sniffing dog to the front door of a home was a Fourth Amendment search also requiring a warrant. As I said in a blog post about this minor victory for the Fourth Amendment, "Any case is a good case if it declines to use the failed 'reasonable expectation of privacy' doctrine."

So, does Smith dispense with our Fourth Amendment interests in phone dialing information? Here's what Justice Sotomayor said about that in Jones:

[I]t may be necessary to reconsider the premise that an individual has no reasonable expectation of privacy in information voluntarily disclosed to third parties. This approach is ill suited to the digital age, in which people reveal a great deal of information about themselves to third parties in the course of carrying out mundane tasks.... I would not assume that all information voluntarily disclosed to some member of the public for a limited purpose is, for that reason alone, disentitled to Fourth Amendment protection.

I'm going to do you a favor here: Don't bet on Smith v. Maryland.