Around 10 years ago, we drove through Maine and spent a half hour or so looking at Bowdoin College. Mid-October.I would say cell phones and social media will be number 1 before it's all said and done.
There was nobody there. A beautiful Fall day, and their main quad was empty. After around 15 minutes, someone walked by. Since I'm shameless, I approached him and asked where everyone was. Short answer: in their dorms. What social life they had was indoors. On a computer or their phones.
So, I agree. Cell phones and social media. (My excuse: I'm in my mid 70s.) College age students whose only social contact was electronic? What a world.