I'm a programmer (developer/engineer/whatever), been programming since I was about 10, but I've not encourages nor discouraged computer use for my kids. I figure the computer is there and they will pretty much decide how much they are into it.
I have to also confess that I've thought of developing a kids website that my kids can play with. What are your experiences or thoughts here?
But if you decide to allow/encourage children to use these instruments, I believe that a secure social network aimed to protect children is better than Facebook with its lousy privacy rules and controls, where they could meet a lot of risks.
In this particular case, just because they're fine without it doesn't mean they might enjoy themselves and have better lives (whatever that means) with it.
So I'd let them know it's there, perhaps explain what it is but go no further, give them the path as an option but let them choose where and what they do.
I did this once (totlol.com). My kids love it, so do others, but I can't say it brought joy to our family. 2 cents? Don't.
While at home they need down time and time to be bored. It's an essential element of developing your own personality.
They've got 400 years of books to read as well, the sooner they start on that the sooner they will finish.
Social networks make sense for adults because we're removed from my family, friends, peers by geographic proximity and time .. plus we have too many casual "friends" to network with face to face constantly.
Kids? not so much. Kids can make friends within few minutes. Let them play outside, somewhere safe.
Sounds like a useless version of Twitter :-)