FILTERED DRAGNETS AND THE ANTI-AUTHORITARIAN FOURTH AMENDMENT

Filtered dragnets are digital searches that identify a suspect based on the details of a crime. They can be designed to withhold information from law enforcement unless and until there is a very high probability that the individual has committed the offense. Examples today include DNA matching, facial recognition from photographs or video of a crime, automated child sexual abuse material detection, and reverse geolocation (geofence) searches. More are sure to come, and their wide-scale use will be irresistible to improve the low rates of criminal detection that currently afflict many communities. However, filtered dragnets imperil society precisely because they detect crime too well. Sudden increases in the detection of criminal conduct will intensify the pathologies of American criminal justice: namely, that too many marginally harmful acts are criminalized, crimes are punished too harshly, and police and prosecutors have too much discretion. If nearly everybody commits some technical violation of criminal law that can be easily detected and harshly punished, all Americans will be at the mercy of the constable's pity. These threats are not well constrained by current Fourth Amendment jurisprudence, based on privacy rights, because filtered dragnets detect crime without revealing irrelevant details. Thus, Fourth Amendment theory and doctrine must strengthen the anti-authoritarian objectives endowed in its roots. A search conducted with a filtered dragnet should be considered reasonable only if it is administered in an evenhanded manner, and a subsequent seizure of a person is reasonable only when the misconduct is abhorrent enough to justify arrest and imprisonment.