Systems and methods for reducing accuracy of web bugs are disclosed. In some implementations, a method includes, at a computing device, identifying an incoming electronic message addressed to an intended recipient. The incoming electronic message includes a plurality of content items provided by a content provider. The method also includes, before the intended recipient reviews the incoming electronic message, reducing accuracy of user activity tracking by the content provider, by: requesting on a modeled temporal basis, a download of a first media content item in the plurality of media content items. In some implementations, the first media content item is invisible to the intended recipient.