In September 2013 the drinking water supply in many parts of Dakar, Senegal was disrupted. Hundreds of households were in dire straits – while at their neighbour’s place the water was gushing from the faucet. To solve the problem, a group of programmers spontaneously developed a simple Facebook app. Through a contact list, people who needed water could be hooked up with people who had it. Via a Facebook message, they would then organise to pick it up. Within four days the Facebook app had enabled more than 700 water deliveries.