Physicians expressing opinions on medical matters that run contrary to the consensus of experts pose a challenge to licensing bodies and regulatory authorities. While the right to express contrarian views feeds a robust marketplace of ideas that is essential for scientific progress, physicians advocating ineffective or dangerous cures, or actively opposing public health measures, pose a grave threat to societal welfare. Increasingly, a distinction has been made between professional speech that occurs during the physician-patient encounter and public speech that transpires (...) beyond the clinical setting, with physicians being afforded wide latitude to voice empirically false claims outside the context of patient care. This paper argues that such a bifurcated model does not sufficiently address the challenges of an age when mass communications and social media allow dissenting physicians to offer misleading medical advice to the general public on a mass scale. Instead, a three-tiered model that distinguishes between citizen speech, physician speech and clinical speech would best serve authorities when regulating physician expression. (shrink)