The process of argument may be aimed at persuading an agent to perform a particular act which its proposer views as advantageous to their own interests. The proponent's primary motivation for desiring a given action to be executed may, however, differ radically from those advertised reasons given as justification: in particular, an agent may wish to hide the true purpose of proposing an action, since knowledge of such motives would be very likely to result in it not being performed. This scenario has been described as the proponent agent having a “hidden agenda”, and is a widely-recognised phenomenon in persuasive argument settings such as electioneering. The purpose of this paper is to consider various issues arising when an agent seeks to assess a case for action presented to it as motivated by a potentially damaging hidden agenda.