When Video Chat is Free.
Your children have never known a world dominated by communication via digitally presented text. Sure, people still read and write, but communicating with your peers by text is now considered archaic. Video calling another individual is de rigueur; group video chats are equally common. People dive in and out of group video conversations with ease. Three-dimensional presentation of these conversations is not uncommon, though maybe still a luxury in the developing world.
Here I am, pining for the forceful, eloquent prose of the typographic age, and Alex already has us projected into a post-digital world of ubiquitous video. Sadly, I believe his vision is substantially correct. To me, this bespeaks a frightfully dystopian world.