Not many years ago,families used to have one telephone and TV in the living room,and there was no such thing as a home computer.
Nowadays,all those items can be found in most teenagers' bedrooms.Behind closed doors,teens can have private conversations,and they can turn the TV on to any channel they like.If they are curious,they will use the internet to explore places they never imagined existed,Having this equipment in their own rooms means an increase in privacy for the kids.