the_user_formally_known_as_glennbo
Because if someone is backing up their entire hard drive to the cloud, they should be thinking about exactly what info is on that hard drive, and then all the other questions make more sense. If you are backing up a drive that has nothing but wave data on it, then it's no big deal, but if you are backing up your primary boot drive, then you should pay closer attention to what all the implications are.
Who backs up their entire hard drive to the cloud? I mean I'm sure there are those who do, but its certainly not most people. I've seen the front ends of a few different cloud-based solutions and have done installs/setups of a few for folks over the years. All those that I've seen more of less default to wanting to backup document folders only. Yep you can configure them to backup the whole drive, but you have to know what you're doing to get that setup. It probably should go without saying that most people don't know what they're doing when it comes to that sort of thing. So they click the defaults and let it go.
Now if someone is keeping a word doc in their documents folder that has every password they ever used and every credit card account number they own and their mother's maiden name and social security number yada yada yada, I would argue that's very likely to be someone that was going to be at elevated risk for identify theft long before they ever bought a computer.