We warmly thank Ball Christian, Bazzi Laura, Becker Lilian, Bieri Cornelia, Bovet Stefanie, Cachelin Elodie, Christen Silvan, Eberle Stefanie, Hötzendorfer Peter, Lepdor Florence, Marfurt Josephiné, Meier Petra, Mhidi Mehdi, Nicoli Fanya, Sigam Bansoa, Stojanovic Tamara, Tobler Hannes, Zollinger Larissa and Züst Lea for their decisive contribution to the recruitment of participants in the streets of Lausanne and Zurich in September 2014.