I don't think privacy is necessarily even the worst issue - it's the constant time suck, the lack of interest in other human beings, the inability to talk to people that the smart phone encourages/enables.

I kept my son on a flip phone for years. He was fine with it - I actually think he got a lot out of it.

But very recently he sat me down, and said, "I need a smart phone". And we got him a used Android phone.

Luckily he's VERY aware (maybe because of me, or seeing his friends constantly with their face on the phone?) of the dangers of smart phones. On his own, he installed the Stay Free app, which provides reporting on how much time you're spending on the phone. He has very few apps on it, even deleted the browser which I didn't know you could do.

It's a very, very difficult problem, and most especially with teens nowadays. I think you're ABSOLUTELY justified in being extremely strict with the phone. You don't want your kid to be in the majority of teens that doesn't know how to talk to people, that has their head constantly at a 90 degree angle.

Yes, it will impinge on their social life. Maybe try to get with other parents to coordinate limits. People are desperate for solutions/alternatives to this.

That whole, "they need to learn self control" thing is easy to say, but it's very hard for teens to do, especially with a product as addictive as the smart phone apps are designed to be.