The following stats come from this website: http://geniusrecruiter.com/2012/03/01/social-media-stats-for-students-and-colleges/
- Teens age 13-17 now use triple the data usage (320 MB per month)
- The average teen sends 3417 text messages per month (Wow!)
- Voice usage among teens declined from an average of 685 to 572 minutes per month
These stats don't necessarily mean that anything negative is happening, but it does indicate that students are spending more and more time online. Some other stats from this site support the idea that more time is also being spent on social networking.
As a teacher, the only time I think of social networking as negative is when students are ignoring me or the lesson to engage in it.