This article investigates why moments of semiotic silence, or minimal engagement, occur in Facebook practices among Filipino migrant workers engaged in grassroots organizations working for migrants’ rights. We investigate how members and leaders of these organizations subjectively and intersubjectively assess moments of semiotic silence through their discourses. Taking a sociolinguistically grounded chronotopic approach, we show how they make sense of these moments by invoking a multiplicity of space-times related to sociopolitical constraints, their working situation, communication with family, and the organizing of migrants. This study provides empirical data, highlighting the importance of identity, materiality, and media ideology in understanding grassroots social media practices and political engagement. On this basis, we come to understand a broader range of ways in which migrant workers use or do not use social media in relation to community involvement and public discourse. (Social media engagement, grassroots organizing, chronotope, identity construction, media ideology, materiality, migrants’ rights)