Currently, when a report is shared you are unable to see who shared the report and admins cannot see a list of reports shared. We need to ability to manage reports shared and remove if necessary. We have a report that was shared out to all admins that is not accurate and we have no way to remove.
We just ran into this as well. We needed to make changes to some saved layouts, but cannot delete the originals that were shared. I'm not able to see who created and shared them.