“Greensboro in the early nineteen-sixties was the kind of place where racial insubordination was routinely met with violence. The four students who first sat down at the lunch counter were terrified. “I suppose if anyone had come up behind me and yelled ‘Boo,’ I think I would have fallen off my seat,” one of them said later. On the first day, the store manager notified the police chief, who immediately sent two officers to the store. On the third day, a gang of white toughs showed up at the lunch counter and stood ostentatiously behind the protesters, ominously muttering epithets such as “burr-head nigger.” A local Ku Klux Klan leader made an appearance. On Saturday, as tensions grew, someone called in a bomb threat, and the entire store had to be evacuated….

So one crucial fact about the four freshmen at the Greensboro lunch counter—David Richmond, Franklin McCain, Ezell Blair, and Joseph McNeil—was their relationship with one another. McNeil was a roommate of Blair’s in A. & T.’s Scott Hall dormitory. Richmond roomed with McCain one floor up, and Blair, Richmond, and McCain had all gone to Dudley High School. The four would smuggle beer into the dorm and talk late into the night in Blair and McNeil’s room. They would all have remembered the murder of Emmett Till in 1955, the Montgomery bus boycott that same year, and the showdown in Little Rock in 1957. It was McNeil who brought up the idea of a sit-in at Woolworth’s. They’d discussed it for nearly a month. Then McNeil came into the dorm room and asked the others if they were ready. There was a pause, and McCain said, in a way that works only with people who talk late into the night with one another, “Are you guys chicken or not?” Ezell Blair worked up the courage the next day to ask for a cup of coffee because he was flanked by his roommate and two good friends from high school.

The kind of activism associated with social media isn’t like this at all. The platforms of social media are built around weak ties. Twitter is a way of following (or being followed by) people you may never have met. Facebook is a tool for efficiently managing your acquaintances, for keeping up with the people you would not otherwise be able to stay in touch with. That’s why you can have a thousand “friends” on Facebook, as you never could in real life.

This is in many ways a wonderful thing. There is strength in weak ties, as the sociologist Mark Granovetter has observed. Our acquaintances—not our friends—are our greatest source of new ideas and information. The Internet lets us exploit the power of these kinds of distant connections with marvellous efficiency. It’s terrific at the diffusion of innovation, interdisciplinary collaboration, seamlessly matching up buyers and sellers, and the logistical functions of the dating world. But weak ties seldom lead to high-risk activism.”