For years, I have warned that technology would become the government’s greatest surveillance tool. Politicians always promise new powers will only be used against criminals. Then those same powers gradually expand until everyone becomes a potential suspect. History never changes because governments never voluntarily surrender authority once they obtain it.
The U.S. Supreme Court has now delivered one of the most important privacy decisions in years. In a 6-3 ruling, the Court held that law enforcement’s use of geofence warrants constitutes a search under the Fourth Amendment.
Justice Elena Kagan wrote that people do not surrender their constitutional right to privacy simply because they carry smartphones or enable location services. As she explained, “A cellphone user is not to be viewed as sharing private information with third parties… just by doing the ordinary things cellphone users do.” The Court sent the case back to determine whether the warrant itself satisfied the constitutional requirement of probable cause, but the broader principle is now clear, digital location data deserves constitutional protection.
Geofence warrants represent one of the most sweeping investigative tools ever created. Instead of identifying a suspect first, police define a geographic area and time period, then compel companies such as Google to identify every device that was present. In the Virginia robbery case before the Court, Google initially identified 19 devices located within approximately 150 meters of the crime scene before investigators narrowed the list. These warrants invert the Constitution by allowing police to search thousands of innocent people first and decide who becomes a suspect afterward.
The significance extends far beyond one robbery case. Smartphones constantly generate location histories, travel patterns, religious attendance, medical visits, political gatherings, and personal relationships. The government no longer needs someone to follow you down the street. Your phone already performs that task every minute of every day. Technology companies possess an extraordinary amount of information, and governments around the world increasingly view those databases as investigative gold mines.
This ruling does not end digital surveillance. It simply reminds governments that constitutional limits still exist. Many technology companies have already begun changing how they store location data. Google, for example, has shifted much of its location history storage onto users’ own devices rather than centralized servers, making broad geofence requests more difficult. Law enforcement will undoubtedly seek new methods as technology evolves, because governments never stop seeking additional powers.
The larger trend remains exactly what our computer has warned. Governments burdened by rising debt, political instability, and civil unrest always seek greater control over information. Surveillance expands during every crisis because politicians claim extraordinary circumstances require extraordinary powers. Today it is geofence warrants. Tomorrow it will be artificial intelligence analyzing billions of data points in real time. The battle between personal liberty and government surveillance is only beginning, and this decision represents one of the few occasions where the courts have reminded Washington that the Constitution still matters in the digital age.