Some US airlines are now even using it instead of boarding passes, claiming it's more convenient. There has also been wider use of affect recognition, a subset of facial recognition, which claims to'read' our inner emotions by interpreting the micro-expressions on our face. As psychologist Lisa Feldman Barret showed in an extensive survey paper, this type of AI phrenology has no reliable scientific foundation. But it's already being used in classrooms and job interviews -- often without people's knowledge. For example, documents obtained by the Georgetown Center on Privacy and Technology revealed that the FBI and ICE have been quietly accessing drivers license databases, conducting facial-recognition searches on millions of photos without the consent of individuals or authorization from state or federal lawmakers.

Unfamiliar faces aren't welcome at Beijing public housing projects. To prevent illegal subletting, many have facial recognition systems that allow entry only to residents and certain delivery staff, according to state news agency Xinhua. Each of the city's 59 public housing sites is due to have the technology by year's end. Artificial intelligence startup Megvii mentioned a similar public housing security contract in an unspecified Chinese city in filing for an initial public offering in Hong Kong last week. The Chinese startup, best-known for facial recognition, touts its government dealings, including locking down public housing to curb subletting, as a selling point to potential investors.

All of China's 1.4 billion citizens are about to be put under greater scrutiny as the country prepares to launch its'social credit score' scheme. The project rates citizens based on their behaviour, and those who do not play by the rules are added to a list that prohibits them from certain luxuries. Fears are growing regarding the ethical implications of scheme, with some questioning the morality of the big-brother culture. The government is likely to use its rapidly growing surveillance network to enforce the system, with some academics growing concerned that it may be manipulated to enforce the ideology of the ruling Communist party. Completing community service and buying Chinese products is thought to improve it whereas fraud, tax evasion and smoking in non-smoking areas can drop it.

There are few places better positioned to become a "smart city" than Singapore. That's an easy statement to justify. Singapore is an island city-state just 30 miles across that has been governed by the same party for decades. Putting the implied democratic flaws to one side, the geography and political stability of Singapore have aided the city in preparing for the future. Two years ago, those preparations got a name: "Smart Nation," an ambitious program to push the city, its residents and its government into the digital age.

I got to talk to Jane Jacobs once, toward the end of her life, an interview that is mentioned, in its properly Lilliputian proportion, in Robert Kanigel's new biography, "Eyes on the Street: The Life of Jane Jacobs" (Knopf). She was one of three people I have met in a lifetime of meeting people who had an aura of sainthood about them, the others being Iona Opie, the British folklorist who collected children's rhymes, and I. F. Stone, the independent American journalist. What they had in common was a sort of radiant self-reliance. They could say an obvious thing--that children are citizens of another country, that all governments lie--with the conviction that comes from having really found it out. They spoke for many, because they thought for themselves. Iona Opie made hanging around schoolyards to find small variants in jumping-rope rhymes seem essential to understanding humanity, and Izzy Stone made you feel unpatriotic for not printing your own biweekly page of political commentary. The ability to radiate certainty without condescension, to be both very sure and very simple, is a potent one, and witnessing it in life explains a lot in history that might otherwise be inexplicable--for instance, how a sixteen-year-old girl could lead the French Army to victory. Jane Jacobs's aura was so powerful that it made her, precisely, the St. Joan of the small scale. Her name still summons an entire city vision--the much watched corner, the mixed-use neighborhood--and her holy tale is all the stronger for including a nemesis of equal stature: Robert Moses, the Sauron of the street corner. The New York planning dictator wanted to drive an expressway through lower Manhattan, and was defeated, the legend runs, by this ordinary mom.