While I have been implementing and maintaining Service Management projects for many years, I only recently ran into the following problem. I searched the Community and the Atlassian documentation for an answer but nothing popped up. After some experimentation, I figured out what was happening and I want to share this with the community. It drove me crazy for several days trying to figure out what was happening. I hope that this information saves you some time.
Problem: I created a JSM project and noticed that there were several customers already populated in my Customer list. I wanted to remove these Customers but couldn't figure out how to do that. The Atlassian documentation said to go the Project Settings -> People and remove them, but they didn't appear in that list. In fact, there was no one yet in the People screen. I was the only person who should have had access to the project. There didn't seem any way to remove these "phantom" users from the Customer list.
Solution: After experimentation, I realized that the people in the Customer list were there because they belonged to a Group that had "Browse Project" and "Create Issue" permission to the project. Once I removed "Create Issue" from that Group, those Customer disappeared from my Customer list.
Derek Fields
derek.fields at rightstar.com