Ogolnopolski Strajk Kobiet (All-Poland Women's Strike) is a grassroots campaign established in Poland in 2016 in response to the proposed tightening of abortion laws but which also engages with broader social, feminist and women's rights issues. Using a critical approach to multimodal discourse analysis, this article analyses the postings of the campaign on its main social media platform, Facebook, investigating closely the types of multimodal speech acts, referred to here as 'communicative acts', employed therein. The article examines the forms that such communicative acts take and the broader functions they fulfil within the (online and offline) context of the campaign. The observed communicative acts contribute towards and indeed enact the protest quite directly, forming an important part of the campaign's discourse of feminist dissent.