Privacy, Anonymity, and Accountability in Ad-Supported Services

In this talk, I will address three aspects of user privacy in advertiser-supported, online services. First, I present the design of a novel browser plug-in that enables anonymous search. Next, I consider economic aspects of user privacy from the point of view of the operator of an advertiser-supported website. Finally, I present recent work on "accountability" in online activity, where the goal is to hold website operators responsible for appropriate handling of users\´ sensitive information rather than to prevent users from ever providing information that might be misused.