Web 2.0 services include sharing and collaborative technologies such as blogs, social networking sites, online office productivity tools, and wikis. Wikis are increasingly used for the design and implementation of pedagogy, for example to facilitate experiential learning. A U.S. government-funded project for system security risk assessment was conducted using a wiki powered by MediaWiki. Participants were geographically disbursed students, faculty, and industry partners with highly diverse backgrounds and expertise. The focus of this research was the experiential learning practiced by students carrying out the work of the project. Through the use of a wiki as a mass authoring tool, students constructed knowledge in the form of an annotated bibliography of extant systems security literature. Results from a student survey offered convincing support for the use of the wiki's influence on students' experiential learning, particularly through the benefit of observation and reflection, as well as the motivational influence of social norms. Lessons learned and possible extensions of the approach described in this study to other educational settings are discussed.