American teens, social media & privacy

"Teens are sharing more information about themselves on social media sites than they have in the past, but they are also taking a variety of technical and non-technical steps to manage the privacy of that information. Despite taking these privacy-protective actions, teen social media users do not express a high level of concern about third-parties (such as businesses or advertisers) accessing their data; just 9% say they are “very” concerned.
Key findings include:
Teens are sharing more information about themselves on their social media profiles than they did when we last surveyed in 2006:
91% post a photo of themselves, up from 79% in 2006.
71% post their school name, up from 49%.
71% post the city or town where they live, up from 61%.
53% post their email address, up from 29%.
20% post their cell phone number, up from 2%."

Source:  Pew Internet & American Life Project, 21st May 2013