Online backup systems should, generally, be ok even if temporarily compromised since they will keep copies of stuff even if you delete it. (Dropbox does this for FREE accounts.)
The problem is backing up big stuff -- I've got my working docs backed up the wazoo (I can even backup large multimedia/game projects to Dropbox) but my photo and media libraries are unmanageable.
"The only secure computer is one that's unplugged, locked in a safe, and buried 20 feet under the ground in a secret location..."
-- Dennis Huges, FBI.
The same goes for USB disks. I prefer to have one of my backup drives inactive most of the time and out of plain sight (in case of theft from my home).
Because he was a mac user, he should've been using Time Machine. It can be hosted on a network partition at your home so you don't even have to remember to plug in a backup drive. And in OS X 10.8, you can assign multiple disks and it'll keep them all up to date if they're accessible at the time. So one can be on your home network, another at your work network, and yet another on a physical drive that you can keep locked away in a safe or something. Just pull it out once a month to back up all your macs.
Echoing this, because it happened to me. And in that case I was very happy I backed up my most important things to some sort of "cloud" (a combination of GMail, creative portfolio stuff on a few webservers, projects I had sent to friends and a couple of those filelocker sites).
Additionally, SD Cards turn out to be some the most resilient data storage media I've personally witnessed. Probably helped it was encased in a camera, which was kaput, but the photos on it were fine, not even data-bent.
And a year later I found in a box of my damaged CDs some more treasures on a couple of really old DVD backups that actually still worked :D (I never bothered to really unpack the boxes of partially blackened and warped CDs--there's no need in the age of MP3, and after a while you've really seen enough boxes of sooty crap smelling like burnt plastic)
My basic lesson from this is: spread your data and risks around.
Though, none of that stuff was encrypted. Just the stuff I kept online was passworded and do friends count as a two-factor auth? :-)
Sorry to hear about your house fire. I wonder, would it be feasible to bury a small portable hard drive in the garden or something, and have a conduit running up near the house? It'd be cute to have a USB port on the wall which you plug your laptop into when you want to make a physical backup. No thief (or house fire) is going to trace down a USB lead that's poking out from the ground or wall.
It's taking Apple's "Time Capsule" branding to the extreme literal sense.
Hahaha! No idea if it'd be feasible (my apt is at 1st floor anyway, I have no garden), but it'd be cool as hell to load your backups onto a USB cable that goes underground :-)
Every week or so a potential client comes to us and describes, in one way or another, this general scenario. They ask "what if someone breaks into my server that I am backing up to you, and then using the SSH key, logs into my rsync.net account and wipes all of that out as well.
So for the last 6 years or so (we've been providing offsite backup since 2001) we have offered "pull backups" to our customers that request it. We give them our public SSH key, and we log in and rsync their data back to us.
Also, RE: the previous comment about not having your data consolidated to a single provider, we run an ad on reddit regularly making the same point:
One additional thing you can do is add a "command=..." parameter to your ssh authorized_keys file to limit what can be done with that key. For example, you can set it to run a script which only allows new files to be added to the backup, but not deleted.
Happy to see someone else not willing or not able to let files disappear in the cloud. For photo and media I keep them on two 500Gb usb drives, one at home and one at office, and keep them in sync with the wonderful tool unison.
I have redundant backups. Everything's gets backed up locally with Time Machine very regularly. Then nightly (or more, depending on volume) it gets shipped off to Backblaze.
It gives me quick responses if I need to restore something, but if my house blows up, I'm only $100 and a FedEx visit away from having everything back.
The problem is backing up big stuff -- I've got my working docs backed up the wazoo (I can even backup large multimedia/game projects to Dropbox) but my photo and media libraries are unmanageable.