From a really interesting article on social graphs by Maciej Ceglowski. He’s pretty dissatisfied with current versions:
You might almost think that the whole scheme had been cooked up by a bunch of hyperintelligent but hopelessly socially naive people, and you would not be wrong. Asking computer nerds to design social software is a little bit like hiring a Mormon bartender. Our industry abounds in people for whom social interaction has always been more of a puzzle to be reverse-engineered than a good time to be had, and the result is these vaguely Martian protocols.