> Iron Mountain initially agreed to turn over Nine PBS’ data, but it eventually backtracked and claimed that OSS owned the data it stored. Because of this, Nine PBS now has no choice but to sue Iron Mountain, too, to ensure the data is not deleted.

This does make sense. I'm guessing the first request some rep just went sure its you're data why not, but in reality, it's OSS's data, and you paid OSS to store it. It's also likely encrypted in someway.

TLDR still, is especially when it's a reasonable amount of data, just have more than 1 backup.

I store my belongings with a storage company. They rent facilities from a property owner. The storage company goes under while my stuff is still in the storage unit. I go to the property owner and say my stuff was in there. They say, no, that's owned by the storage company. Incorrect - the belongings were owned by me the entire time, the storage company was just holding it for me. I need to prove it was mine, but I don't lose property rights just because it's in someone else's possession.

Likewise if I store data with a cloud provider. Sure, Iron Mountain shouldn't just offer it up without proof, but if I give them notice of a legal case they should be sure to hold on to it, and if I win the case they need to hand it over to me. All I need to do is provide proof that I am the rightful owner of those goods.