Reports on one of the first efforts to apply value-sensitive design (VSD) to a large-scale real-world software system. We sought to improve informed consent in Web-based interactions through the development of new technical mechanisms for cookie management. We describe our VSD methodology, explicate criteria for informed consent in online interactions and summarize how current browsers fall short with respect to those criteria. Next, we identify four goals for the redesign of current browsers. These goals, in turn, initiate an iterative design process that lies at the heart of the VSD methodology wherein we move among the design and implementation of new technical mechanisms, formative evaluation and the design goals coupled with the criteria for informed consent online. Key mechanisms include peripheral awareness of cookies and just-in-time interventions. At various phases in the design process, we implement our design improvements in the Mozilla browser (the open source for Netscape Navigator).