Currently, we can share a file with individual users and only the system admin can delete shared files. We need a more flexible system. For example, we should be able to assign users to groups like Support, Sales, etc... Each user should be able to be assigned to multiple groups. When a user is assigned to a group, it would automatically share his transfers with the group or groups he's assigned to. However, group sharing could be disabled on a per-transfer basis and there could be an option for the default behavior. Each group should have a group admin. The group admin could delete any files shared with the group.