As the Serb forces swept into Kosovo during the Balkan War in the late 1990s and began their violent campaign of ethnic cleansing, Australian surgeon Craig Jurisevic decided to go there to use his medical skills to help the victims. He ended up joining the Kosovo Liberation Army and taking up arms against the Serbs. Along the way he witnessed horrific brutality - and says he was forced to carry out a mercy killing on a fatally injured woman. His book is called "Blood On My Hands".
In the 1970s Mohsen Sazgara used an early form of social networking to support the Islamic Revolution in Iran. Today he's using state of the art technology to undermine the government he helped to put in power.