A lot of "decent backup systems" would be vulnerable to this too. Say you back up all your local stuff to a RAID that you've mapped as a drive, as well as a mapped Google Drive?
It's still all toast.
That level of backup would handle any kind of physical failure - a dead drive, the destruction of your house, the failure of Google... but still, this thing would kill it.
There's only so much you can expect from a person when it comes to keeping their personal documents and family photos.
I mean obviously, if you're running a company you need a real backup solution, but for family files or a one-man-show business? There is no reasonable precaution.
This type of thing only works because the backup user has identical permissions to the backup contents as the user being backed up (because they're the same).
It wouldn't work on any system where the backup user is a separate, privileged process that is the only one with write access to the stores of backed up files.
ZFS with a snapshot script is a good way to implement this for a networked drive on Samba, since it's implicit, automatic, and the point at which it hits would be really really obvious since your snapshot sizes would suddenly explode. The same story is true of volume shadow copy (but MS idiotically limits the user's ability to set a known and trustworthy shadow copy schedule).
It's still all toast.
That level of backup would handle any kind of physical failure - a dead drive, the destruction of your house, the failure of Google... but still, this thing would kill it.
There's only so much you can expect from a person when it comes to keeping their personal documents and family photos.
I mean obviously, if you're running a company you need a real backup solution, but for family files or a one-man-show business? There is no reasonable precaution.