Millions of people outraged about the treatment of refugees express this via Twitter. Few know what actions they can take. We used a behavioural principle called the “identifiable victim effect” to help mobilise action on behalf of Amnesty International. A ‘command centre’ in London monitored tweets of outrage relating to the refugee crisis and a team on the ground in the camps filmed personalised messages from refugees replying to the tweets within hours of being posted. The personal messages succeeded in inspiring our supporters to go beyond outrage and take action. The outcome; 850,000 petition signatures presented at the United Nations, perfectly achieved the mission to position Amnesty as the global human rights group best placed to help with the refugee crisis.