The Australian Constitution does not include a right to free speech but an implied freedom of political communication. The implied freedom has recently been a site of flux, as the High Court has embraced structured proportionality and articulated more clearly the underlying values. This paper considers the challenges posed for the changing nature of the implied freedom by ‘extreme speech’, especially hate speech and speech that advocates law breaking, such as civil disobedience. The paper considers recent decisions such as Clubb v Edwards; Preston v Avery (2019) recognising the role of values such as privacy and dignity in determining the permissible limits on free political communication. Advocacy of law breaking may not protected by the implied freedom e.g. Michael Brown & Ors v Classification Review Board . This contrasts with the position in the US in Brandenburg v Ohio (1969). The paper considers which approach is most appropriate given the nature of the implied freedom.