I think the threshold would be, did Linode take "reasonable" precautions in protecting the servers in question. Just like the landlord or bank. So long as they take reasonable precautions, they can't be held liable.

You can expect for your landlord to keep their copy of the key in some sort of lockbox, but you aren't going to expect them to keep it in a pressure-sensitive safe, guarded by movie-style lasers and a German Shepard.

You expect a little more security out of your bank.

The real question is: why were services that act like bitcoin banks storing their coins on Linode in the first place.