When I was little, the rules about how far I could go were geographic. I wasn't allowed to cross the street or go so far from home that I couldn't hear the dinner bell. I was allowed to cross and play in the alley. There was also a half hour of TV rule on weeknights which was strictly enforced.
Today of course, most of the limits are technical and virtual. What sites can you go to? How long can you spend on the console? On Youtube? How old do you have to be before you can have a Facebook account? Can you Skype with people that you don't know from school?
Frankly, parenting in a digital age is a whole new world.
Can I go to school at home? Can I try to science experiment that I learned on Youtube?