This paper looks at current grassroots efforts to revitalise Yucatec Maya, an indigenous language of Mexico, in social media and more specifically on Facebook. In contrast to the limitations of institutional language promotion, the inclusion of Maya on Facebook shows the possibilities that social networks offer not only for actual use of minoritised languages but also for advocacy and activism, particularly among indigenous youth. The concept of heteroglossia is also introduced to explain the plurilingual practices of youngsters in Yucatán based on their increasingly complex linguistic repertoire. The main argument is that grassroots initiatives of language revitalisation that focus on local contexts, horizontal linguistic practices, and speakers as final agents are particularly significant in a country with deeply entrenched vertical and often tokenistic policies aimed at the promotion of indigenous languages and cultures.