Social media provides an inexpensive way for interest groups to inform and mobilize large audiences, but it is puzzling why organizations would spend time posting about activities like litigation that do not depend on public opinion or mobilization. We argue there are two reasons interest groups post about judicial advocacy on social media. First, organizations provide information about the courts on social media to build credibility and recognition as a trusted source of information. We hypothesize that membership groups will be less likely to use social media in this way than non-membership public interest organizations. Second, organizations use social media to claim credit for activity in the courts in order to increase their public and financial support. We expect that this strategy will be used most frequently by legal organizations. Using an original dataset of millions of tweets and Facebook posts by interest groups, we find support for these expectations.