1) The document discusses how youth engage with social media and online communities through "hanging around", "messing around", and "geeking out" to extend friendships, pursue interests, and gain expertise. 2) It explores how social networking and digital tools can facilitate new forms of social action and activism among youth, such as organizing online campaigns and fundraising. 3) Several examples are provided of student-led projects that use social media to raise awareness for social and environmental causes on a global scale.