This chapter presents the ‘We Act: Informed Collective Activism Regarding Real-life Problems’ project which, since 2012 and originating at the Institute of Education of the University of Lisbon (IE-ULisboa) in Portugal, has brought together an international network of teachers and students strongly involved in promoting active citizenship and Eco and Social Justice in their communities. By integrating components of development, action, and research, the project aims to empower teachers and students to undertake informed and negotiated actions, addressing social and environmental problems related to science and technology. Through ‘We Act’, students are encouraged to engage in investigative and democratic problem-solving activities, supported by artistic initiatives and the use of Web 2.0 tools. This text describes different aspects of this project, namely its origins and foundations, aims, implemented actions, community of practice, and main results.