We have official BOE policies on BYOD, but I can't get them to you quickly. Speaking to the practical side of high school life- they can use cell phones in the library and cafe. They are supposed to be off in the halls. They can be used in class if teacher directed. 

I see a lot of social media use in the library. It certainly is the bane of a teen's existence (esp girls) and I see parents and coaches texting students constantly. I discourage it, but find you really can't monitor it effectively without creating more problems and tremendous ill will between us (Teacher vs Student). When you have lots of rules, there is a lot of wordsmithing over violations and consequences and exceptions. 

When we first rolled out, many teachers were not supportive- especially those who like to play 'gotcha' for passes and the like. As we have been living with it this year, I see students are, for the most part, able to learn to balance time and place and priorities. It is part of everyone's world, and the world they will transition to when they leave us. They need time to practice new skill sets where there is a strong safety net. 

Another tipping point is the referral for discipline- admins get overwhelmed by minor infractions and the culture is evolving. And, I think the need to teach/model responsible use is invaluable. Of course the 'gotcha - caught doing wrong' groups have been disempowered, but it begs the question of what our purpose is in the big picture view.