Guardian Witness 24/7 coverage, 2 offices, UK, USA, Sydney, open assignment allows contribution, like, share, tweet on topics and events, through videos, pictures or text, report events first hand in unique way, comment on one another create conversation McLuhan 1967 De Sola Poole 1977 Gaultung & Ruge Walter 1995 Winer 1994 Prensky 2001 Leadbetter 2009 Plunkett 1008 Gillmor 2004 ull 2006 Irvine 2006 Shirky 2012