The technique in question had involved a secretive unit called the Special Demonstration Squad, which trawled birth and death records to find details of children who had died in infancy, secured their birth certificates, and then obtained driving licenses and other documents so that they could masquerade as protesters and sympathizers, gaining the trust of the groups—sometimes by having intimate relationships with members for years. But such tactics were only useful when dealing with targets with no serious counterintelligence capabilities. The danger of finding a death certificate matching the supposedly “live” individual has increased as a result of digitized public records. Instead, intelligence agencies today do something even more offensive to modern social mores: They look for people who are never going to apply for passports or create any digital traces of their own.

A favorite category is people born with profound disabilities, who spend their lives in the care of others. A disabled man who has no bank account or mobile phone and requires round-the-clock care for his most basic and intimate physical needs is going to be invisible to the outside world. But he has a birth certificate, which can be used to build an identity for someone else’s undercover life. This practice raises profound ethical questions in an era when most people feel that those with disabilities have inalienable human rights. What may have been acceptable 20 years ago may seem outrageous and career-killing in 20 years’ time.