Probably about half the time as a 10-16 year old (after 16, my parents stopped caring about what I did or where I went at all) I was banned from computer use for various reasons. That didn't stop me though, I'd go to bed at 10pm, wake up at 2am, then use it until school.
Was four hours of sleep every night good for me? Probably not, but kids can get away with that sort of thing.
(I was also banned from having my own email address, using IRC or any sort of chat program, having my own blog... Basically my parents were deathly afraid that I would talk to any of my peers, even though they were sending me to public school. Most of my computer bans were for violations of these rules. Circumventing enforcement of these various rules was a significant driving factor in my self-education)