Of the 40% of internet users who have faced harassment online, young adults, women, and racial minorities are especially vulnerable, experiencing more severe harassment and experiencing it more often. This article attempts to reconcile the increasingly urgent calls for students to compose in public spaces online with the reality of potential harassment. Compositionists should avoid relying on a Habermasian understanding of the public sphere and instead embrace a political, ecological approach to public writing that recognizes publics as the result of the interactions between multiple texts and actors, and that attends to the ways in which power relations alternately shape, constrain, and enable those texts and actors. This model equips students with a more sophisticated framework for understanding internet publics, and will ultimately empower them to make informed rhetorical choices about which public networks to enter, ensuring not just more effective rhetorical action but safer online experiences.