I happened to catch an excellent story on ESPN's SportsCenter this morning. It was about college athletes getting in trouble for posting pictures and other controversial content on social networking sites like Facebook or MySpace. There are interviews with athletes, coaches, and administrators.
In some instances the athletic departments banned their athletes from using the sites. A female athlete admits to using Facebook under a fake name to get around the ban. Other colleges make it a point to educate their student athletes about the dangers of posting photos that the entire world can see, even if the students assume they're only for friends to view.
You can see the complete story on the ESPN website at: http://broadband.espn.go.com/ivp/splash2?id=2991868
This would make for an excellent classroom discussion with all students, not just athletes.