In 2022, the U.S. Supreme Court ended a federal right to abortion access in the country. Ensuing disparate abortion legalization throughout the country made pertinent the question of whether and how digital platforms would promote or demote abortion-related content. In this study, we explore folk theories in the domain of abortion-related speech. We investigate conceptualizations and heuristics of how users think platform governance and shadowbanning—a practice in which content is demoted without a user knowing about it—work. Through in-depth interviews with 19 pro- and anti-abortion activists in the United States, we examined how activists thought platforms adjudicated their content. We found that, while the two ideologically disparate communities of activists developed differing folk theories on platform governance, they overlapped in thinking that they were censored by platforms precisely because of what they believed in and had shared on social media. This feeds into a general assumption that platforms’ decisions are ideologically motivated, a phenomenon we refer to as ideological suspicion. Our results show that when users do not know how platforms render content decisions about abortion-related speech, this can lead to troubling feelings of marginalization, isolation, and censorship, but it can also motivate activists to ensure their beliefs are heard in a hostile platform environment.