Partnering is a common business practice which takes advantage of outside expertise and allows companies to focus efforts on their core competencies. A key component of partner coordination is information sharing. Whether a partner is a traditional partner such as a supply vendor, where the firms use information technology (IT) as a facilitator for information sharing, or an IT partner to which an organization outsources certain IT functions, IT allows partners to open information borders to each other. While beneficial in many ways, this sharing also creates security vulnerabilities which should not be ignored. In this study, we examine forensic accounts of numerous past security incidents in an effort to learn more about the impact of partner relationships on security risk, and to suggest factors which may be indicators of increased risk.