The threat of digital disinformation is a staple in discourse. News media feature examples of digital disinformation prominently. Politicians accuse opponents regularly of slinging disinformation. Regulators justify initiatives of increasing corporate and state control over digital communication environments with threats of disinformation to democracies. But responsible regulation means establishing a balance between the risks of disinformation and the risks of regulatory interventions. This asks for a solid, empirically grounded understanding of the reach and effects of digital disinformation and underlying mechanisms. This article provides a set of questions that a responsible approach to the regulation of disinformation needs to address.