Colorado Supreme Court Condones Law Enforcement Use of Dangerous Reverse Keyword Warrant

On Monday, Oct. 16, the Colorado Supreme Court issued its ruling in Seymour v. Colorado, a case about the constitutionality of the relatively new police technique of “reverse keyword warrants.” The Court ultimately side-stepped many of the most important issues in the case by ruling that the good-faith exception to the warrant requirement excused the police’s use of the warrant even if it was unconstitutional.

“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.

In its amicus brief, EPIC argued that reverse warrants are per se unconstitutional. The Fourth Amendment requires that search warrants identify a specific subject or place to be searched based on probable cause to believe evidence will be found in that location, but reverse warrants turn this principle on its head by ordering companies like Google to search through every single user’s location and search history to identify who was in the right place at the right time or who searched for a specific search term. In effect, these warrants allow the police to search everybody to find evidence, which the Constitution specifically prohibits. EPIC explained that this was especially dangerous in an era after the Dobbs decision as states increasingly criminalize seeking, or even crossing state lines to obtain, an abortion.

While the Colorado Supreme Court addressed some issues, such as ruling that a warrant was indeed required and that the warrant used was sufficiently particular, it declined to decide whether the warrant was supported by probable cause or constitutional because it said the police obtained the warrant in good faith, so excluding the evidence it generated would not achieve the Fourth Amendment’s aims. This represents a missed opportunity to rein in a new, dangerous police ability.

Multiple justices disagreed with the majority opinion’s reasoning. They cautioned that the decision could provide law enforcement with unprecedented access to individuals’ private lives and flew in the face of the Constitution.

EPIC regularly submits amicus briefs in cases involving Fourth Amendment rights.