In an important new privacy ruling, a federal judge in Massachusetts last week suppressed a “precise video log” of the comings and goings at a private home, which law enforcement generated by training a hidden pole camera on the home’s driveway for a whopping eight months. Law enforcement undertook this surveillance without a warrant or probable cause, and the court held that this constant, long-term, and digitally searchable surveillance violated the defendants’ Fourth Amendment rights.

The court’s decision expressly relied on recent Supreme Court decisions on digital rights, and it powerfully demonstrates how those decisions alter the calculations that law enforcement must make when deciding to undertake warrantless digital surveillance.

In June 2018, the United States Supreme Court issued a landmark digital privacy ruling, holding that police must obtain a warrant before asking our cellphone companies to turn over information showing where we’ve been in the past. In that case, Carpenter v. U.S., police had obtained—without a warrant—cell site location information revealing Mr. Carpenter’s movements over a period of several months.

The Fourth Amendment provides that people have a right to be secure in their persons, houses, papers, and effects against unreasonable searches. Put simply: the government cannot invade our personal lives without proper justification.

Generally, and subject to a few exceptions, that means the government must prove to a judge that there is probable cause that someone committed a crime and get a warrant before invading their privacy. Among other details, the warrant must describe the place to be searched and what evidence is supposed to be found. 

In this case, U.S. v. Moore Bush, the police installed a video camera on a utility pole outside the defendants’ house in Springfield, Massachusetts. The police collected surveillance video from the camera over a period of 8 months. The camera could pan and zoom, was trained on the family’s driveway, and was used to create a precise, searchable record of the family’s activities. When police tried to use this information against the defendants in court, the defendants filed a motion to suppress, alleging the warrantless surveillance violated their Fourth Amendment rights.

For many decades, courts viewed the Fourth Amendment as a protection against government’s physical trespass upon our homes and other physical places. But as technology has become more pervasive and sophisticated, enabling new forms of government tracking and surveillance, the Supreme Court has come to analyze our reasonable expectation of privacy to decide whether a search had occurred, looking beyond physical trespass. The modern Fourth Amendment protects people, not places, the Court has held. In Carpenter the Court held that our rights are safeguarded even when we go about our business in public, a crucial ruling as technology like face surveillance creeps into government use nationwide.

But what is a ‘reasonable expectation’ of privacy?

To show that an unconstitutional search has occurred, a defendant has the burden of proving two things. First, she must have exhibited an actual, subjective expectation of privacy. Second, this expectation has to be one that society is prepared to recognize as objectively reasonable.

In this case, the judge analyzed these two prongs and concluded that defendants Nia Moore Bush and her mother met both.

First, the court noted that the defendants’ choice of neighborhood and home showed “that they did not subjectively expect to be surreptitiously surveilled with meticulous precision each and every time they or a visitor came or went from their home.” This led to the conclusion that the defendants manifested a subjective expectation of privacy in the whole of their movements–and their guests’–in and out of their house over the course of eight months.

Second, the court analyzed whether this expectation was objectively reasonable. To answer this question, the court divided its reasoning into two parts.

In the first part, the District Court relied on Carpenter’s reasoning that a person ought to have some objectively reasonable expectations of privacy when in spaces visible to the public. Importantly, Judge Young concluded that in light of the landmark Carpenter ruling, he was no longer bound by  First Circuit precedent in a case called U.S. v. Bucci. That decision authorized the use of pole cameras without warrants.

In the second part, the judge took into account that Carpenter incorporated Justices Alito’s and Sotomayor’s concurrences in the 2012 case US v. Jones. In that case, the Court held that the government’s warrantless GPS tracking of a vehicle violated the Fourth Amendment. When viewed as a whole, these cases (and the concurrences) offer three principles that the court used to determine whether the use of the pole camera was constitutional.

First, excessive surveillance that gives the government the power to assemble unlimited data on many people at once not only chills associational and expressive freedoms but also is susceptible to abuse.

Second, courts have to carefully scrutinize the capabilities that permit law enforcement to search through this data and give access to information that would be otherwise unknowable.

And third, society is not prepared to accept the long term and constant monitoring of people’s movements on public streets.

When applied to the facts in the instant case—namely, continuous video recording for 8 months, the focus on the driveway and front of the house, the ability to zoom in and read license plate numbers, and the creation of a digitally searchable log—Judge Young found the defendants’ expectation of privacy was objectively reasonable.

The opinion lays out two main reasons to support this conclusion.

First, surveillance using pole cameras unconstitutionally chills the exercise of First Amendment rights like religious, political, and associational activities. The chilling effect becomes more explicit in this case, because one’s home is the central place where we exercise these freedoms.

Second, the camera improperly allowed unconstrained and perfect surveillance of the defendants’ home and routines for more than eight months. This enabled the government to unlawfully piece together intimate aspects of their lives. And while each of the activities surveilled would not give rise to a reasonable expectation of privacy, the analysis has to take this information as aggregated and compiled by the government.

Crucially, Judge Young noted that the surveillance enabled by the pole cameras, especially the feature that allowed law enforcement to record the defendants’ movements in one digital log ready to be searched at any time, could never be achieved by human beings without the assistance of powerful technology, significantly impacting the reasonable expectation of privacy test.

New surveillance technologies like pole cameras and automation tools like face surveillance allow the government to collect and analyze vast amounts of information, enabling remote, cheap, and pervasive tracking of millions of people at a time. This aggregate, constant, and intrusive surveillance, as Judge Young describes it, gives unprecedented powers to law enforcement. With power comes responsibility, and in this case and others, the Fourth Amendment offers a clear path for responsible balancing of government investigative need with personal privacy and free speech rights: Get a warrant.

This blog post was written by Technology for Liberty Program Policy Counsel Emiliano Falcon-Morano.