Hi Nicolas,
Yes you can run report to check what data is being backed up for a user or for a computer.
To run a report
1 On the navigation bar, click Reports.
2 On the Reports pane, select the report you want to run.
3 In the Task pane, under Reports Tasks, click Run report now.
4 Select the appropriate filters for the data you want to include in the report from
the following available filters. Some of these filters are disabled depending on
the report selected.
i)Computer
ii)User
iii)Profile
iv)Days
5 Click OK to run the report. The report can be printed or saved before it is closed.
6 Click OK to close the report.
For more information on reports please go through DLO Admin guide
http://www.symantec.com/business/support/resources/sites/BUSINESS/content/live/DOCUMENTATION/6000/DOC6413/en_US/DLOAdminGuide_EN.pdf
Pages 197 to 201
Good luck!!
Regards,
Srivishnu