The paper studies students’ perceptions of teacher authority among members of class WhatsApp groups shared by students and educators. The qualitative analysis draws on 35 in-depth interviews with high-schoolers studying in a religious educational framework, characterized by a conservative view of teacher authority. The findings demonstrate that the use of WhatsApp as a central channel of student-teacher interaction indeed undermines teacher authority. In particular, it traces the development of six common response patterns which allow students to defy teacher authority on WhatsApp: ignoring the messages, leaving the group, transferring to another mode (e.g., voicemail), defamation of the teacher on a parallel group, defiant discussion devoid of body language, and ambiguous cynical responses. Such reactions are unique to social media groups in platforms such as WhatsApp, and are virtually non-replicable in the physical classroom.