On: I shipped a word processor that formatted the hard...

[meribold]

Agree about Google and Dropbox, but rsync.net has read-only snapshots so you can call them and ask for old files.

[rsync → meribold]

This is correct. I can't speak to what you can do with google, but you can, in fact, call (or email) rsync.net and ask for old files.

By old files, that can mean any snapshot schedule you choose to set up (daily, weekly, monthly, quarterly ...).

[lucb1e → meribold]

And Tarsnap.

Not sure if rsync can do local encryption these days? So I guess 'for the paranoid' (as Tarsnap's tagline is), Tarsnap with write-only keys might be better.