The reason I'd put it behind a password is that WordPress sites get hacked when they're not closely monitored, and this probably wouldn't be a site that I would be monitoring regularly.
FaceCrook has servers all over the world doing exactly that, no telling how many backups they have in use.
Digital information is never safe, I worry about my 5 bucks in my checking account I can't sleep at night.
I am not5 much of a computer guy, but I was involved in some mainframe work. We ran computers in tandem and just switched between them as they were mirrored but not communicating all the time. If one side went down, the other was fine. I have no idea if that would work on forums though. Does @Beth Gallagher have any ideas?
I used to do a little product management, and oversaw the RAID line of stuff. "Mirroring" was one of the 4 ways to configure a bank of hard drives to do real-time backups. I'm sure it's all changed since then...Better/Faster/Cheaper.