There are few things as revealing as a person's search history, and police typically need a warrant on a known suspect to demand that sensitive information. But a recently unsealed court document found that investigators can request such data in reverse order by asking Google to disclose everyone who searched a keyword rather than for information on a known suspect.
In August, police arrested Michael Williams, an associate of singer and accused sex offender R. Kelly, for allegedly setting fire to a witness' car in Florida. Investigators linked Williams to the arson, as well as witness tampering, after sending a search warrant to Google that requested information on "users who had searched the address of the residence close in time to the arson."
The July court filing was unsealed on Tuesday. Detroit News reporter Robert Snell tweeted about the filing after it was unsealed.
Court documents showed that Google provided the IP addresses of people who searched for the arson victim's address, which investigators tied to a phone number belonging to Williams. Police then used the phone number records to pinpoint the location of Williams' device near the arson, according to court documents.
The original warrant sent to Google is still sealed, but the report provides another example of a growing trend of data requests to the search engine giant in which investigators demand data on a large group of users rather than a specific request on a single suspect.
"This 'keyword warrant' evades the Fourth Amendment checks on police surveillance," said Albert Fox Cahn, the executive director of the Surveillance Technology Oversight Project. "When a court authorizes a data dump of every person who searched for a specific term or address, it's likely unconstitutional."
The keyword warrants are similar to geofence warrants, in which police make requests to Google for data on all devices logged in at a specific area and time. Google received 15 times more geofence warrant requests in 2018 compared with 2017, and five times more in 2019 than 2018. The rise in reverse requests from police have troubled Google staffers, according to internal emails.
Google said Thursday that it works to protect the privacy of its users while also supporting law enforcement.
"We require a warrant and push to narrow the scope of these particular demands when overly broad, including by objecting in court when appropriate," Google's director of law enforcement and information security, Richard Salgado, said in a statement. "These data demands represent less than 1% of total warrants and a small fraction of the overall legal demands for user data that we currently receive."
The company declined to disclose how many keyword warrants it's received in the last three years.
Worries about search warrants
Reverse search warrants like geofence warrants are being challenged across the US for violating civil rights. Lawmakers in New York have proposed legislation to make these searches illegal, while in Illinois, a federal judge found that the practice violated the Fourth Amendment
Keyword warrants aren't new. In 2017, Minnesota police sent a keyword warrant to Google for information including name, address, telephone number, Social Security numbers and IP addresses related to people who searched for a "Douglas [REDACTED]" in a fraud investigation.
Todd Spodek, the attorney representing Williams, said he plans to challenge the legality of the keyword warrant issued in June. He hasn't seen the document yet but said he intends to argue that it violated Williams' rights.
Spodek said he's seen more of these types of warrants being issued in criminal investigations and worries it could lead to wrongful accusations in the future.
"Think of the ramifications in the future if everyone who searched something in the privacy of their own home was subject to interviews by federal agents," Spodek said. "Someone could be interested in how people die a certain way or how drug deals are done, and it could be misconstrued or used improperly."
Typically, probable cause is needed for search warrants, which are associated with a suspect or address. The demands for information are narrowly tailored to a specific individual. Keyword warrants go against that concept by giving up data on a large group of people associated with searching for certain phrases.
After investigators linked Williams to the arson through the keyword warrant, they sent Google another warrant specifically for his account, finding that he looked up phrases like "where can i buy a .50 custom machine gun," "witness intimidation" and "countries that don't have extradition with the United States."
This detail was discovered after executing a warrant on Williams, rather than the other way around, in which investigators looked for everyone who searched those phrases.
Google is also facing criticism for complying with broad data requests such as geofence and keyword searches.
"If Google stored data in a way that was truly de-identified, then they also couldn't give it to the government," the Electronic Frontier Foundation's surveillance litigation director Jennifer Lynch said. "Google's not setting up their system or changing their practices in a way that could prevent these kinds of searches."
Because of how keyword warrants work, there's concern that innocent people's online activities will be swept up in the requests. People have been arrested for being in the wrong place at the wrong time because of geofence warrants, and attorneys are now worried it could happen for searching on Google.
Both Lynch and Spodek said reverse search warrants are being used more and more frequently by police departments, and call the practice unconstitutional.
"A lot of people could be searching for various terms," Spodek said. "That alone should not be enough."