My 11y DD has plenty of access to technology - computer, iPad, iPhone, Kindle, an old DS, a shared PS3...
But she does not have "free range" access. I have never had to tell her not to use them as she is, so far at least, not obsessed with any of them. They are not allowed to be used after bedtime, at the dinner table, etc.
She hasn't yet been taken over by the devil - she is still happy and social, spends time with friends and family happily without them, does a range of other activities inside and out....
Her computer is used effectively for school work primarily - Powerpoint, Word, Excel and Publisher for presentation of work, Scratch for programming, photo and video editing.....
Her iPhone for keeping in touch with friends and family, but also for music and occasionally for games (latter not often)...
Ipad - for social stuff, face time, quick internet searches, a few games, listening to music, photos/video, watching a film..
DS rarely used these days tbh. Family S3 used mainly as a Bluray player, but sometimes for games - Harry Potter spells one, or singing ones.
I have complete access to her phone and iPad (and computer) inc her messages, emails, etc. She knows this and it is a condition of her having them.