As demonstrated by recent media reports concerning the Australian Public Service Social Media Policy and the Australian Rugby Union's dispute with Israel Folau, social media often blurs the line between our professional and personal lives, and means that employers want to control what we do and say on social media. This is an issue which directly affects Australian teachers, whose professional obligations have always extended beyond their immediate work environments. Does social media mean that teachers are never 'off the clock'? This article examines the current law relating to control of teacher behaviour and comment on social media. It analyses the implied freedom of political communication discussed in the 2019 High Court decision of "Comcare v Banerji," and its ramifications for teachers and their employers. Additionally, using case studies involving social media policies of authorities which control teacher professional conduct, it considers whether such policies constitute lawful and reasonable directions, or whether they could be challenged as infringing teachers' rights to a personal life.