Fossil fuel companies hold immense power to change the climate, impact public perceptions, and influence policy. Revoking their social license to operate is one strategy by which the public may resist harm done by the industry. Social license is built upon establishing legitimacy, credibility, and trust, and is something that companies must earn from impacted communities to operate successfully. The present study uses a qualitative content analysis of tweets from fossil fuel organizations, as well as a selection of the replies to those posts, to examine how social media may be used to question these organizations’ social license. Results show that replies consistently voice doubts about legitimacy and credibility. Implications for using this strategy in public interest campaigns are discussed.