Big Data Searches and the Future of Criminal Procedure

The vast volumes of our consumer data that companies retain to target advertising, train artificial intelligence products, and predict our preferences can also help solve crimes and identify unknown perpetrators. Two powerful strategies for cracking cases involving unknown perpetrators, keyword warrants and geofence warrants, direct businesses to disclose devices that performed incriminating keyword searches or that were present during a crime. The new digital search strategies drawing on corporately held big data are sparking conflicts and confusion in the courts because a suspect is not named, spurring originalism-influenced analogies to 1700s-era general warrants. Evaluating digital searches through the lens of a time before electric powerexisted-much less electronic data-makes no sense but remains alluring because of Romantic Luddism, a tradition of anxiety over technological change and nostalgia for the past. Advancing beyond Romantic Luddism in Fourth Amendment interpretation, this Article offers a newanalytical lens for big data search strategies that are evolving with technology. How crimes are perpetrated in the digital age has evolved. Our concept of the Fourth Amendment's requirements, including what constitutes probable cause and particularity in big data search warrants, must evolve as well. ThisArticle frames the concepts of digital probable cause and collateral impact to address conflicts in the courts over big data searches using keyword and geofence warrants to identify unknown perpetrators. The Article draws on the analogy of John Doe DNA warrants to explain how advances in science and technology can give new grounds for probable cause and particularity whena perpetrator's identity is unknown. The Article also frames the concepts of collateral impact and collateral harm to evaluate overbreadth concerns and empathy disparities regarding the impact of searches on persons not involved with the crime. The Article's proposal enables controlled use of big data search strategies such as geofence and keyword warrants while forestalling abuses, such as mass surveillance of political protesters or hunting for abortion seekers