Documents and Libraries are always shared with external and internal users in a collaborative platform like Office 365 SharePoint. From a security standpoint, most potential breaches start with access permissions that are not regulated. In order to streamline all access permissions to SharePoint online, you can use the effective permissions reports for sites, users & groups, lists, folders and list items that give you the detailed information assigned on the SharePoint objects namely, lists, folders and list items, with the level of permissions assigned and whether these permissions are assigned directly or through a SharePoint group.

The OneDrive Non-Owner Permissions report shows the list of users who are not owners but have access to the folders and files within the personal site of a particular user. It displays users with permissions assigned on folders and files of a personal OneDrive store. Another useful report is the OneDrive Permissions report that shows OneDrive site-based access rights. This report shows the list of users who have access to any particular OneDrive personal site within Office 365.

A full inventory of SharePoint Office 365 gives you reports on how your organization has structured its content for collaboration and how they are being used. The List, List Item and Site inventory reports gives you the detailed information about the lists, list items and sites that are available in your SharePoint online environment along with their usage details.