When should courts follow legal precedent and when should the law change? This is a debate that underlies this month’s contrary decisions about the constitutionality of government collection of telephone call metadata under section 215 of the USA PATRIOT Act. And despite this week’s dual holdings in favor of the government—on this issue and on the issue of laptop border searches—a judicial consensus may be emerging that the Fourth Amendment must evolve along with technology and government surveillance capabilities.

In the first phone metadata opinion, issued December 16th in the case of Klayman v. Obama, Judge Richard J. Leon of the District Court for the District of Columbia held that Smith v. Maryland did not validate the mass collection here. For those new to this issue, Smith is a 1979 Supreme Court case that held that phone numbers dialed are not entitled to Fourth Amendment protection because the dialer has no reasonable expectation of privacy in the numbers. Rather, the subscriber cannot expect privacy in, and assumes the risk that, the phone company will disclose the numbers she dials to other people, including the government. Smith has its defenders and detractors. George Washington University Law Professor Orin Kerr and I have debated its continuing viability on these very pages and Justice Sonia Sotomayor has suggested that the time has come for Smith—and the so-called third party doctrine based on it—to come to an end.

Judge Leon agreed with the view that Smith is irrelevant to modern bulk metadata collection programs involving far more and more detailed information about essentially every American. People do have a reasonable expectation that the Government will not collect and store for five years their telephony metadata for purposes of high-tech data analysis without any case-by-case judicial approval.

Then, on December 27th, Judge William H. Pauley of the Southern District of New York upheld the section 215 program in ACLU v. Clapper, saying that Smith v. Maryland controls for Fourth Amendment purposes. Primarily, Judge Pauley seemed influenced by the idea that the calling records in question were owned by Verizon, and not by the plaintiffs. [That foundational assumption is wrong. The Telecommunications Act defines telephone numbers dialed, information contained in phone bills, and other information relating to the quantity, technical configuration, type, destination, location, and amount of use of a telecommunications service as “customer proprietary network information” and prohibits phone companies from disclosing or using it in statutorily unapproved ways. So, to the extent property rights answer the Fourth Amendment question, US law pretty clearly says that phone numbers dialed belong to the consumer, not the company. Also, they are private.]

Pauley also made the argument that if one man’s dialed phone numbers are not private, than neither are everyone’s. “The collection of breathtaking amounts of information unprotected by the Fourth Amendment does not transform that sweep into a Fourth Amendment search”

It is that purely mathematical view of the Fourth Amendment that I believe may be on its way out. Judge Leon did not accept it, instead holding that a difference in scope is a difference in kind. Nor does Judge Edward R. Korman of the Eastern District of New York in the ACLU’s other defeat of the week, today’s Abidor v. Napolitano decision. Abidor is a challenge under the Fourth and First Amendments to the Customs and Border Patrol (CBP) guidelines and practices for searching electronic devices at the US borders. Judge Korman dismissed the ACLU’s challenge on standing grounds, but nevertheless assessed the merits of the underlying claims. With regards to the Fourth Amendment, the court agreed with the Ninth Circuit in US v. Cotterman that “quick looks” at data do not require any suspicion at all, and then proceeded to assess whether the Fourth Amendment means a comprehensive forensic search of digital data at the border can only be undertaken based on reasonable suspicion.

In concluding that it does not, Judge Korman is pretty dismissive of the plaintiffs’ case, at one point musing that plaintiffs must be “drinking Kool-aid” if they believe that a reasonable suspicion standard will protect their—and their clients’ and sources’—confidentiality, given that low threshold and the fact that the other countries to which plaintiffs travel also perform searches at their borders. Nevertheless, Judge Korman did not say that the Fourth Amendment will never require reasonable suspicion at the border, despite that long-standing doctrine. Rather, he points out that CBP’s current capacity for such suspicionless searches is naturally limited, as the Ninth Circuit recognized in Cotterman. While holding that forensic searches do require reasonable suspicion, the opinion would not have any practical effect on current practices, the appellate Court said, “because the extremely limited resources available to conduct comprehensive forensic searches necessarily limits such searches to situations where some level of suspicion is present.” Judge Korman then goes on to say, “I would agree with the Ninth Circuit that, if suspicionless forensic computer searches at the border threaten to become the norm, then some threshold showing of reasonable suspicion should be required.” Korman just doesn’t think that’s factually true right now.

This may be a big deal. Judge Korman seems to be saying that mass surveillance world requires a more robust Fourth Amendment doctrine than we currently have.

Back in 2007, Judge Richard Posner said something similar about mass surveillance and the Fourth Amendment in United States v. Garcia, a case involving GPS location tracking. The defendant had claimed that the technique could be used in mass and thus warrantless use should be prohibited. In rejecting the Fourth Amendment claim, Posner opined that the meaning of a Fourth Amendment search must change to keep pace with the march of science, and yet, the amendment cannot sensibly be read to mean that police shall be no more efficient in the twenty-first century than they were in the eighteenth. The challenge is to strike the right balance when new technologies enable, as the old (because of expense) do not, wholesale surveillance.

Technological progress poses a threat to privacy by enabling an extent of surveillance that in earlier times would have been prohibitively expensive. Whether and what kind of restrictions should, in the name of the Constitution, be placed on such surveillance when used in routine criminal enforcement are momentous issues that fortunately we need not try to resolve in this case.

The time for these “momentous issues” has come. This year’s NSA revelations show that—to a far greater extent than was publicly known—we are living in that mass surveillance world. A consensus seems to be emerging that the Fourth Amendment must evolve along with technology and government surveillance capabilities, and that it is the job of the lower courts to investigate and to rule accordingly. Indeed, if lower courts slavishly follow the closest analogous Supreme Court case on hand, rather than seriously consider whether facts, policies and practices on the ground have changed, higher courts will not benefit from the best fact-finding and the best legal reasoning incubated in the lower federal courts.

The fact that a government agency can technologically and economically accomplish the feat of collecting data on every phone subscriber, and making profiles of hundreds of millions of people, is an unprecedented power. The government used to be limited in its power to investigate and profile people by economics and technology. Increasingly, only the law would limit such practices. Will courts employ the Fourth Amendment to do privacy-protecting work that economic disincentives performed in the past? Recent opinions, from the concurrences in United States v. Jones, to today’s decision by Judge Korman suggest they will. Here’s to seeing that happen in 2014. Happy New Year.