Usable Privacy Controls for Blogs

Web 2.0 applications such as blogs, wikis and social networking sites have challenging privacy issues. Many users are unaware that search engines index personal information from these sites and offer public access to collected data. As a consequence, privacy invasions are rampant. In this paper, we demonstrate that tag-based privacy policies are a usable and flexible privacy control method for Web 2.0 applications. Content owners express their privacy policy in terms of tags on content objects; the system then applies the policy to objects based on the tags assigned to them. We implemented tag-based privacy controls as a plugin to the WordPress blogging system, and conducted a user study to measure whether users could efficiently address real-world privacy concerns using tag-based policies. Despite limited time and training, a third of the participants chose the tag-based policy tools. These users were able to perform privacy-related tasks with the same accuracy and increased speed using our tag-based privacy controls versus per-object privacy controls.