Negative, ableist discourse challenging the rights of people with Down syndrome to receive support services and even to be born regularly arise on social media. This disability community has retaliated against such hate speech with resistance narratives that promote the value of people with Down syndrome, with few other recourses available. This article explores online free speech versus ableism in Australia through a major case study of 60 Minutes Australia Facebook discussions. Analysis identifies types of ableism expressed, types of harm caused and dimensions of grassroots responses. Using Timothy Garton Ash's 2016 work Free Speech as a basis for contemporary analysis, we discuss: to what extent should harmful and offensive comments directed at vulnerable populations be tolerated in the name of free speech; might negative, ableist discourse contribute to any social good; and what mechanisms beyond grassroots resistance narratives might effectively respond to harmful, online ableist discourses.