The past decade has witnessed a growing number of studies illustrating how online teacher communities on social media platforms offer a worthwhile space where teachers can easily exchange teaching ideas, ask questions, collaborate with others, and obtain emotional support. Instead of seeing online teacher communities through rose-tinted glasses like most studies in the existing literature, the present study focuses on identifying the drawbacks of teachers’ uses of social media for professional learning purposes. Data were collected via online observations of an online language teacher community and semi-structured interviews with 30 English language teachers who are professionally making using at least one social media platform. The findings are discussed in terms of the challenges associated with teachers’ professional uses of social media, and, ultimately, the ways in which social media might best be incorporated into teachers’ professional learning practice are suggested.