Journalist Fasman (known from ‘The Unpossessed City’) delivers a deeply reported and sometimes chilling look at mass surveillance technologies in the American justice system. He notes that police departments in more than 100 cities use Shotspotter, an app that employs acoustic sensors mounted on traffic lights to identify and locate the sound of gunfire; speaks to an aeronautical engineer whose company makes drone-mounted camera systems that can surveil an entire city; and visits an Israeli security firm wanting to equip cameras that automatically read license plates with voice and facial recognition software and sell them to private citizens. Because many of these technologies are new, Fasman explains, there are few policies in place to regulate them, and even fewer penalties for ignoring the policies that do exist. A section on China’s “tech-enabled repression” of Uyghur Muslims and its financing and building of Ecuador’s emergency response network illustrates the threat of mass surveillance in countries with “weak institutions or scant regard for civil liberties,” while a portrait of citizen activists in Oakland, Calif., who fought back against a planned citywide monitoring system offers lessons on how to “forestall the surveillance state.” Fasman avoids alarmism while making a strong case for greater public awareness and tighter regulations around these technologies. This illuminating account issues an essential warning about a rising threat to America’s civil liberties.