It would be very useful if there is a way to check ownership of content on space restore.
At the moment, when a space is restored in Confluence, the ownership of pages is automatically associated with the users that have the same username from the source instance, this accidentally may cause the content to be associated/visible to the wrong user who got the same identical username on the target instance.

For example, if there are two instance with two different user directories, each directory has a username 'mikej', but the owners of these accounts are two different people who happen to have the same username (e.g. Mike Jhonson and Mike Jay, both have 'mikej' as username). When a space is exported to XML from the first instance and then restored on the target instance, the owner of the pages are automatically is assigned to the second user which expose data to the second user that he shouldn't have access to.

What may help is to have a pre-check mechanism and offer the admin the options to manually or automatically associate content to users on the target instance when restoring the space xml backup.