The document discusses the various social media platforms used by teens at Truckee High and their popularity. It notes that while Facebook was once popular with teens, it is no longer, and MySpace has declined significantly. The most widely used platforms among teens today are Instagram, which allows sharing photos; Vine, for sharing short videos; and Snapchat, which sends photos that disappear after a limited time. These platforms allow teens to update each other individually about what they are doing in lieu of group text messages.