Whether reverse keyword search warrants violate the Fourth Amendment to the U.S. Constitution and the Colorado state constitution.
“Reverse warrants” are a dangerous new type of search warrant increasingly used by police to investigate the sensitive data of thousands or millions of innocent people in hopes of identifying a suspect. There are two main kinds: geofence warrants, which allow police to identify whose devices were in a certain area at a certain time, and reverse keyword warrants, which allow police to identify who searched certain keywords, phrases, or addresses online.
The police only started using reverse warrants in the mid-2010s, but few courts have publicly ruled about whether they are constitutional, and the outcomes of those cases have been mixed. EPIC and other privacy and civil liberties organizations believe they are broadly unconstitutional, and some states have introduced bills to make them illegal. Reverse warrants turn the normal search process on its head in a problematic way. Instead of developing suspicions about a person based on factual evidence and then applying for a warrant to search that person more closely, such as looking through their home, car, search history, or phone, reverse warrants involve looking through the search history or location history of thousands, millions, or even billions of innocent people in the hopes of finding a suspect.
These searches expose too many people to police scrutiny and have resulted in investigations of demonstrably innocent people. In effect, they are identical to “general warrants,” the hated colonial British practice of signing a search warrant that only specified the crime to be investigated and left discretion to officers of who and where to search for evidence.
Reverse warrants have been made possible by the enormous dossiers of sensitive information collected by private tech companies like Google. Google knows where almost everyone is at any given time given the ubiquity of its phones and apps and its design choices that make it difficult to turn off location tracking. Similarly, Google knows what many people have searched over time because of the primacy of Google Search. These treasure troves of personal information are the sources targeted by reverse warrants.
This is the first case about whether reverse keyword warrants are constitutional. Unknown arsonists set fire to a house in Colorado that led to the deaths of five people. The police engaged in increasingly invasive surveillance of people across Colorado and the country, using cell-site simulators (fake, police-operated cell phone towers) to capture people’s phone numbers and communications, “tower-dump” warrants that identify all of the devices that connect to a specific cell phone tower, a geofence warrant, and multiple reverse keyword warrants. They even bought people’s data from the data broker Fog Data Science. All-in-all, police searched and seized information related to devices that belonged to thousands of people, all without identifying a suspect, until they executed their third and final reverse keyword warrant, which searched through billions of Google users’ search histories to find users who had searched the address of the home that was burnt down. This led them to identify the defendant in the case, Mr. Seymour.
During trial, Mr. Seymour—represented by a team of attorneys including attorneys from the National Association of Criminal Defense Lawyers—moved to suppress the evidence against him that came from the reverse keyword warrant, arguing that the warrant was unconstitutional. The trial court judge denied the motion without issuing a written explanation, so Mr. Seymour’s legal team appealed directly to the Colorado Supreme Court. The EFF submitted an amicus brief in support of Mr. Seymour’s appeal, explaining why reverse keyword warrants violate the First and Fourth Amendments: broadly, they allow police to search through people’s sensitive information without meeting the necessary requirement of establishing particularized probable cause for each person, and they risk chilling people’s First Amendment right to search for information by making them fear that their searches could look suspicious to law enforcement in the future.
In its amicus brief supporting Mr. Seymour, EPIC explained that there would be dangerous consequences to ruling that reverse keyword warrants are constitutional. One consequences is that the rules the court sets for reverse keyword warrants won’t stop at the borders of Colorado. As the first court to evaluate the constitutionality of reverse keyword warrants, the Colorado Supreme Court’s ruling will influence other courtsacross the nation and the legal departments of the large technology companies that carry out reverse keyword warrants on behalf of the police.
EPIC’s brief also discusses how reverse keyword warrants may harm people seeking to use the internet to search about abortion and reproductive health care, especially after the U.S. Supreme Court’s Dobbs v. Jackson Women’s Health opinion. People have a First Amendment right to search for abortion-related topics, whether to procure an abortion, become more politically informed about the topic, or even just to learn about related topics such as managing miscarriages or other health concerns, but the existence of reverse keyword warrants unconstitutionally chills this right by making people afraid to search because it could subject them to law enforcement scrutiny. Though abortion is currently legal in Colorado, the Colorado Supreme Court’s ruling will affect courts in states where it is not. Colorado residents and healthcare providers may fear helping out-of-state residents procure abortions—though it is legal to do so—because they do not understand the jurisdictional limits of police in anti-abortion states. And Colorado residents and entities could get embroiled in investigations from out-of-state reverse keyword warrants.