Communication by public authorities during a crisis situation is an essential and indispensable part of any response to a situation that may threaten both life and property. In the online connected world possibilities for such communication have grown further, in particular with the opportunity that social media presents. As a consequence, communication strategies have become a key plank of responses to crises ranging from epidemics to terrorism to natural disaster. Such strategies involve a range of innovative practices on social media. Whilst being able to bring about positive effects, they can also bring about a range of harmful unintended side effects. This include economic harms produced by incorrect information and a range of social harms that can be fuelled by myths and rumours, worsening negative phenomena such as stigmatisation and discrimination. Given the potential for such harms, one might expect that affected or potentially affected individuals would be able to challenge such measures before courts or administrative tribunals. As this paper demonstrates however this is not the case. More often than not seemingly applicable legal approaches are unlikely to be able to engage such methods. This is often because such measures represent activities that are purely expressive in nature and therefore not capable of imposing any binding legal or corporeal changes on individuals. Whilst some forms of soft law may pose requirements for public officials involved in such activities (e.g. codes of conduct or of professional ethics), they are not likely to offer potentially harmed individuals the chance to to challenge particular communication strategies before courts or legal tribunals. The result is that public authorities largely have a free reign to communicate how they wish and do not have to have to comply with a range of requirements (e.g. relating to form and substantive) content) that would in general apply to most forms of official administrative act.