A teacher facing a high school class today will not see a single student paying attention to the lesson. They will see the tops of the students' heads as they attend solely to their cell phones, texting, shopping, watching movies and catching up on email. I often told my students that I had never seen any job ads asking for people who knew how to use a cell phone, but I'd seen plenty for engineers, accountants, nurses, etc.--none of which they'd be qualified to do ignoring lessons to play with their phones.
the sad part is the phone use is happening in the workplace as well, young people 20 somethings, play on the phone a lot, then complain that they have way to much work to do.