That's kind of surprising given how their hardware model is setup, with pods of HDDs that are filled up and then essentially archived away. I guess the amount of space freed up is enough that it makes sense to open those pods back up for writing.
Huh, I didn't know that. My first line of 'oh shit I deleted a thing' is Time Machine, since it's right there next to my external monitor and won't require waiting for a download.
One of the reasons I switched to Crashplan. Their Java client is pretty terrible performance-wise, but it's still the best cloud backup I've tried.
Your definition of backup...
Which is why I don't solely use Backblaze (fast recovery, medium level of trust). I also backup the same data to Glacier-class S3 (slow recovery, high level of trust) and Time Machine (v. quick recovery, same-site risk).