Should law enforcement have virtually unfettered access to all Americans’ online search histories?

That’s the question before a state district court in Colorado, widely believed to be the first challenge to the constitutionality of the widespread — and growing — use of so-called keyword warrants that compel Google and other custodians of online data to turn that data over to police and other agencies upon request.

The case in question involves a defendant, Gavin Seymour, accused of setting fire to a house at Denver, killing a family of five Senegalese immigrants. Seymour, who was 16 at the time, and two other defendants face 60 charges in the case, including murder.  

Despite having surveillance video of the masked suspects near the home, police were initially unable to identify the teenagers. At first, they subpoenaed cellphone location data using what is known as a “geofence warrant,” which allows officers to obtain data on every cellphone in a specific area during a specific time period. 

Police in Denver then served Google with a keyword warrant, according to court testimony from detectives in the case, asking for any searches of the victims’ address in the two weeks before the fire. Google delivered five accounts that had made such a search, including those of the three defendants.

Seymour’s lawyer, Michael Price, who also is the Fourth Amendment Center litigation director at the National Association of Criminal Defense Lawyers, asked the court to suppress the evidence gathered from Google, arguing that the broad keyword warrant used by investigators is a violation of the Fourth Amendment’s protection against unreasonable search. 

“No court has considered the legality of a reverse keyword search, but its constitutional defects are readily apparent and should have been obvious to all involved,” Mr. Price said in his motion. “It is a 21st century version of the general warrants that the Fourth Amendment was designed to guard against. Just as no warrant could authorize the search of every home in America, no warrant can compel a search of everyone’s Google queries.”

The implications of the case go far beyond the criminal matter in question, especially given the skyrocketing number of such warrants now being issued that compel Google to hand over its customers’ data.

With more and more states rushing to criminalize abortion since the reversal of Roe v. Wade, does law enforcement have the right to seek information on everyone searching for abortion providers? Should officers be able to request information on everyone searching for a permit to carry a concealed weapon just because one holder of such a permit committed a crime? What about cases of civil unrest? Should law enforcement be able to obtain data on all the cellphones that appeared at a specific location during a time when rioting or vandalism occurred at that location?

The answer to all those questions, at least according to civil liberties groups, is no.

A digital civil rights organization, the Electronic Frontier Foundation, argued in an amicus brief filed in the Colorado case that these keyword warrants are even broader than the general warrants and “writs of assistance” that inspired the authors of the Fourth Amendment.

A keyword warrant “provides officers a window into the search queries of a billion Google users — search queries that were entered well before the investigation ever began or the crime even occurred,” the EFF argued. “A warrant like this was not conceivable or possible 20 years ago, much less at the nation’s founding.”

The language of the Constitution’s Fourth Amendment is explicit about search warrants. “No Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized,” the amendment states.

Google is by far the largest recipient of these warrants, primarily because of its dominant share of the search market. Nearly 90 percent of all internet search traffic in the United States is handled by Google’s servers — 100,000 searches per second, or 8.5 billion searches per day globally.

If the person searching has a Google account via Gmail, YouTube, Maps, or any of its myriad other services, the company keeps a record of everything that user has searched for, what videos and images they viewed, what websites they visited, where they have traveled, and who they are. Unless the user takes regular steps to delete that data, the company likely has records going back years to when the user first created the Google account.

During the first half of 2021, Google reported in one of its regular transparency reports that it received 25,000 search warrants from government sources in the United States related to nearly 50,000 accounts. More than 80 percent of those requests generated data that was handed over to law enforcement. Ten years ago during the same period, the company said, it handled 1,896 search warrants related to 3,152 accounts.

A ruling in the Colorado case is outstanding, but states have begun to note law enforcement’s increasing use of these warrants and are taking action. A bill now before the New York State assembly would, for example, be the first in the nation to ban them outright. A coalition of major tech companies — Google and Facebook, among them — has said it supports the measure.

“This bill, if passed into law, would be the first of its kind to address the increasing use of law enforcement requests that, instead of relying on individual suspicion, request data pertaining to individuals who may have been in a specific vicinity or used a certain search term,” the group said.