Sam Gregory is the Programme Director at WITNESS, a project that trains and supports activists around the world to use video safely, ethically, and effectively to expose human rights abuse. He also teaches on human rights and participatory media as an Adjunct Lecturer at the Harvard Kennedy School and is the co-editor of Video for Change (Pluto, 2005). Gillian Caldwell is a campaigner, lawyer and CEO at Global Witness. She is the co-editor of Video for Change (Pluto, 2005). Ronit Avni is a filmmaker, human rights advocate and the founder of Just Vision, a non-profit organisation that documents and creates media about Palestinian and Israeli grassroots leaders involved in peacebuilding. She is the co-editor of Video for Change (Pluto, 2005). Thomas Harding is the best-selling author of Hanns and Rudolf (2013), and the co-founder of Undercurrents, Britain's first video news service. He is a leading voice in international video activism and has written for the Independent, Guardian, New Statesman and New Internationalist. He is the co-editor of Video for Change (Pluto, 2005) and The Video Activist Handbook (Pluto, 2001).