"Backed up" means lots of copies. That should be obvious. "Fireproof" means that those copies are in lots of physical locations. "Secured" means strongly encrypted with keys that nobody else knows. "Recoverable" means that those copies can be obtained and restored in the event of disaster. For your most valuable personal data, you should have at least fireproof, recoverable backups and, preferably, secure them.
Mokalus of Borg
PS - You might be able to get away without securing your backups if they are merely personal, not sensitive.
PPS - You'd be surprised what counts as sensitive, though.