I once lost some personal data despite having 3 different backup tools.
1) the Corporate desktop backup didn't backup my local Exchange folder because it in a different directory to the corporate standard due to an OS upgrade.
2) the TSM backup to the mainframe apparently stopped working because whomever was paying
the IBM license fee decided to stop and the admin cancelled all the backups without notifying me.
3) My Linux network backup failed because the building maintenance guys did a power/generator test and the Linux backup server did not boot
Moral: You can't have too many backups.