The role of hashtags for non-profit causes: the #fridaysforfuture movement

Social movements are gaining increasing popularity, especially those related to environmental protection, partly due to their usage of online social media to disclosure information. Tools like hashtags, which help tag and categorize posts, as well as make them more accessible to other users, are also responsible for their popularity. Therefore, this study aims to analyze how hashtags contribute to information disclosure through online social media, focusing on the social movement Fridays for Future and in the social media platform Twitter. Based on 647 tweets containing the hashtag #fridaysforfuture and 503 comments of these tweets, this research delves into examining the content and format of tweets and their associated comments, aiming to identify those that generate more reactions from users, and more exactly during the lockdown produced by COVID-19. Results indicate that most tweets include contents related to interaction and dialogue with other users, and the most used format is textual. With respect to the analysis of comments (of these tweets), the majority express support for the movement in textual format. Tweets that generate more reactions are those that combine content about action, mobilization, digital strike, and COVID-19 in textual format, along with other hashtags related to sustainability/digital strike and images. Regarding the replies to the comments (of these tweets), only the video format generates a greater number of responses. These results describe how to design a message by a famous social movement, offering valuable insights to empower other social movements in shaping their effective social media strategies.