Security within an organization can often be a challenging task. There are usually multiple levels within an organization, as well as multiple departments that you may have to work with when responding to a security incident. What are the challenges in a grid environment where you may have thousands of users using resources within your organization that you have no control over? Then when an incident does happen (that's not an "if"), how do the organizations within the grid work together to respond to the incident, which can usually have spillover to many sites within the grid. This work addresses the challanges of security measures in the more complex environment of grid computing where there is a distributed user base and multiple physical entities composing a virtual organization. We will cover how the TeraGrid sites deal with coordinated security measures and give some real world examples on actual incidents.