Keyword Searches and the Problem of “Particularity”

The Fourth Amendment requires that a probable cause warrant be issued “particularly describing the place to be searched, and the persons or things to be seized.” But how does one define particularity in the age of digital networks and the cloud?
 
This question acquires fresh urgency after Thomas Brewster of Forbes noticed a court document accidentally unsealed by the Department of Justice. The document showed that the government had asked Google to divulge the identities of anyone who had searched for the name, phone number and address of a sex trafficking victim, as well as her mother’s name, over a 16-day span. Google was also directed to provide Google accounts and IP addresses of those who made these searches.
 
Because such orders are kept under seal, there is no way to know how common they are. One such order made public was in 2020 for any individual who searched for the address of an arson victim in the government’s racketeering case against singer R. Kelly. Two others involved a fraud case in Minnesota and a serial bomber in Austin. 
 
In the case of the sex-trafficked victim, the keyword search – while limited to two people and a small number of searches – also included a request for CookieIDs. These are identifiers that can be used to group together every search from a particular device over a given duration. This gives law enforcement an ability to widen its view, and to see every website the owner of that device has visited.
 
In such a world, unimagined by the Founders, where does particularity end? A computer or other digital device certainly qualifies as a particular object, but its reach is global, allowing for a deep and pervasive search of a person’s interests, beliefs and contacts.
 
To be sure, law enforcement needs tools to catch sex traffickers or bombers. But by their very nature, keyword searches could easily become dragnets in which no particular person or group is the target. Instead, a keyword search can act like a fishing trawler dragging its net along the ocean floor – exactly the kind of open-ended investigation the Founders feared and explicitly forbade.
 
The worst aspect of this practice is that these warrants are executed in secret.
 
PPSA urges the Department of Justice to annually release the number of warrants for keyword searches it has sought and obtained. We ask Attorney General Merrick Garland to issue a policy directive, beyond those currently in place to protect journalists, that would define the scope of keyword searches within precise and necessary limits.
 
States should also codify these standards as well for state and urban police departments.