I present a heretofore untheorised form of lay science, called extitutional science, whereby lay scientists, by virtue of their collective experience, are able to detect errors committed by institutional scientists and attempt to have them corrected. I argue that the epistemic success of institutional science is enhanced to the extent that it takes up this extitutional criticism. Since this uptake does not occur spontaneously, extitutional interference in the conduct of institutional science is required. I make a proposal for how to secure this epistemically beneficial form of lay interference.