The Tumblr Adult Content Ban refers to the massive 2018 policy change where the platform prohibited all sexually explicit material. This decision followed the site's removal from the Apple App Store and led to the infamous 'female-presenting nipples' rule, which quickly became a target for satire due to its specific and often confusing phrasing. Memes regarding the ban typically focus on the platform's automated flagging bots, which frequently tagged non-explicit art incorrectly, and the subsequent mass exodus of users to other platforms like Twitter and Pillow. It serves as a classic internet case study in how major policy shifts can fundamentally alter—or destroy—a site's community and culture.