SOS Brutalism is a distress signal. Since the 1950s, eminent architects around the world have realised buildings expressing an uncompromising attitude. Predominantly, yet not exclusively, they used exposed concrete, or béton brut (hence the term ´brutalism´), for their construction. Today, many of these always-controversial buildings are in danger of demolition or, at least, of reconstruction that often may change their appearance beyond recognition. In recent years, an initiative to protect and preserve this significant global heritage of 20th-century architecture has gained momentum, mainly through the internet. Using the hashtag #SOSBrutalism, the Deutsches Architekturmuseum (DAM, German Museum of Architecture) in Frankfurt on the Main and the Wüstenrot Foundation participate in this campaign, and have developed a vast collaborative research project.