Privacy is not a universal or timeless quality. It is redefined by who one is talking to, or by the expectations of the larger society. In some countries, a woman’s ankle is a private matter; in some times and places, sexual orientations away from the norm are deeply private, or publicly celebrated. Privacy, Ms. Boyd notes, is not the same as security or anonymity. It is an ability to have control over one’s definition within an environment that is fully understood. Something, arguably, no one has anymore.