We were raised and taught to socialize, not to stay on our phones all day. But in this day and age, when my friends and I get together, we end up spending as much (maybe more) time on our phones as we do socializing.
How many adults sleep with their smartphones next to their beds? Do you really want your teen to model your behavior? Hanging out with friends at the mall is one thing, but virtually hanging out 24/7 with a cellphone not only interferes with sleep, but intensifies peer pressure.
These are my observations of my high school as of this writing. I say this because I think it is worth noting that, amongst the majority of the high school, this list tends to change vastly in a rather short amount of time.