[hiAndrewQuinn]

That's actually one of my favorite features. That should never happen under the limited circumstances I use it for. If something goes so wrong that my account actually runs out of money before I notice, then I far prefer the default to be "intruder alert, intruder alert, wipe everything". There's a reason it's marketed as backups for the truly paranoid.

[zarzavat]

Then why bother backing up at all? Buy some gasoline and set your laptop on fire, you'll never get more secure than that.

[hiAndrewQuinn]

For me, personally? I do it for kicks. But in general, there do exist many data loads in the world which are valuable to the holder, valuable enough to be worth the low cost of a backup, up until time T in the future. After T, however, they become more of a liability than an asset to hold. A self-destructing backup model is the obvious fit for such situations. Both the positive-sum and the negative-sum periods need to be considered to truly safeguard your data properly.