their is a new variant ransomware going around I witnessed to many PC being infected and unfortunately some didn't have backups at all and others had backups running but not properly configured so their most important files where lost
a copy on the same HD is not a backup
paying for a backup service doesn't means they actually get backed up
be vigilant and double check that your backup serice is configured properly
Yes, and multiple backups for anything you absolutely do not wish to lose is important. Don't put all your eggs into one basket. For me, an important stuff backup is not only not on the same HD, it's also not on an HD in the same building. I have 2 offsite backups, one using Duplicati to offsite server, and the second on a rotating set of drives stored in a safe deposit box. I also have convenient local backup for quick restores of a mistake or something similar. I also have my data ZFS encrypted so if box is stolen, they can't access it.