This article examines the role of expertise in public debate, specifically the ways in which expertise can be mimicked and deployed as “pseudo-expert discourse” to generate legitimacy for views that have otherwise been discredited. The article argues that pseudo-expert discourse having a clear public health or safety impact should be regulated. There have been some attempts to legally regulate this speech through various means; however, these attempts at regulation have been met with fierce resistance, because of free-speech concerns. The article (...) suggests that these appeals to free speech in the context of pseudo-expert discourse are both misguided and misplaced. Moreover, because speakers with the relevant expertise or perceived expertise are able to secure uptake of their views, they have a moral responsibility to not deceive or mislead audiences, and may also have various legal responsibilities. (shrink)