My 14 y.o. doesn't post, but he does read the blog several times a week.
He's expressed interest in posting once we get another computer, though.
For all I know, he may already have an account, lol...he's an independent one. I haven't restricted him from posting, nor would I. They have computers at his school and we have them over other family members homes.
Again - I don't expect a perfect blog...life isn't perfect. My son's been exposed to a LOT, so nothing really fazes him.
But I love the rules/restrictions here, and I'm glad they're in place.