Last summer, people in big cities came face to face with crying children showing up on posters everywhere, with no other explanation than a disturbing hashtag : #makeachildcry

Very soon, The mysterious portraits got twitter going crazy, with reactions going from puzzled to downright angry.

Two days later, Doctors of the World put an end to all the guessing, claiming responsibility for the campaign with a powerful message. Making children cry meant vaccinating, treating and healing them in countries stricken by war, poverty and diseases. For those children, a moment of pain can mean nothing less than their life saved.

#makeachildcry is an international campaign launched in France, Spain, Switzerland, Greece, United Kingdom, Germany, Netherlands, Portugal, Argentina, Canada and Japan.

The teasing phase was launched as an outdoor poster campaign in the big cities.

The growing conversation made #Makeachildcry the trending topic in several countries and the bad buzz caught the attention of the mass media who started talking about it, getting even more people involved.

After two days of conversations and guessings on social networks, Doctors of the World's message was revealed through online videos, TV spots, press, outdoor posters, banners... all leading to a responsive donation website where people could choose how many children they wanted to make cry, and read true stories about Doctors of the World's young patients.

• Donations increased by 10.4 % after the campaign

• The site is still up and running and donations continue to support Doctors of the World's action for children in the world.

• More than 7 million people reached

• More than 15000 tweets during the campaign

• #makeachildcry became the trending topic on the first day of the campaign

• 23000 new followers on facebook

• 210 articles about the campaign were written in international media