This paper explores the potentially perverse effects of voter microtargeting, delineating how the very same techniques that empower political candidates to be more efficient and effective in their campaigning may also undermine the political and social fabric of the democracies in which those candidates seek office. The first part of the paper reviews the apparent attraction and stated goals of voter microtargeting and the technical processes upon which it relies. The second part draws out the ethical and political implications of the practice, pointing to some troubling empirical findings. The paper considers how microtargeting contributes to (1) an increased willingness and ability to deliver messages on wedge issues that would be extremely divisive in a more public forum; (2) voter discrimination and de facto disenfranchisement, (3) a chilling of political participation due to perceived violations of voters' privacy, and (4) a general trend toward single issue politics that leads to increased partisanship among voters and ambiguous political mandates for elected representatives. The final part of the paper introduces Soap Box: a project (initiated by the author) to develop a website that will act as a clearinghouse for targeted political advertising. The website aims to make these messages available to all-comers, forcing campaigns to account for and reconcile the different positions they present to different audiences. The paper concludes with a discussion of the limits of an approach that seeks to combat the more worrisome aspects of voter microtageting by exposing the tailored messages to greater public scrutiny.