• "Engrossing … His wariness makes Gellman a thorough, exacting reporter; it also makes him a marvelous narrator for this particular story, as he nimbly guides us through complex technical arcana and some stubborn ethical questions … He deploys plenty of metaphors, not to adorn the stakes but to clarify them. He shows how discussions of medieval ramparts and Six Degrees of Kevin Bacon are surprisingly pertinent to the architecture of mass surveillance. His voice is laconic and appealingly wry … Dark Mirror would be simply pleasurable to read if the story it told didn’t also happen to be frighteningly real"

    New York Times