Online reputation systems have become important tools for supporting commercial as well as noncommercial online interactions. But as online users become more and more reliant on these systems, the question of whether the operators of online reputation systems may be legally liable for problems with these systems becomes both interesting and important. Indeed, lawsuits against the operators of online reputation systems have already emerged in the United States regarding errors in the information provided by such systems. In this chapter, we will take the example of eBay’s Feedback Forum to review the potential legal liabilities facing the operators of online reputation systems. In particular, the applicability of the Canadian law of negligent misrepresentation and of defamation will be covered. Similar issues may be expected to arise in the other common law jurisdictions. IGI PUBLISHING This paper appears in the publication, Trust in E-Services: Technologies, Practices and Challenges edited by R. Song, L. Korba and G. Yee © 2007, IGI Global 701 E. Chocolate Avenue, Suite 200, Hershey PA 17033-1240, USA Tel: 717/533-8845; Fax 717/533-8661; URL-http://www.igi-pub.com ITB14047