washingtonpost.com: Schoolyard Face-Offs Blamed on Facebook Taunts

Twice this month, students at Walt Whitman High School in Bethesda have used their fists to settle disputes that arose on Facebook. [...] Teens are conducting an increasing share of their social lives electronically, via text-messaging, e-mail and social networking sites such as Facebook. Threats, harassment and bullying have followed them online. Although such behavior is not new, research suggests that it is expanding rapidly, and educators and lawmakers seem resolved to pay closer attention to the words students exchange online while off campus.