What is unfair? It seems completely normal and what courts are for sorting out. Iron mountain is acting exactly how I would want them to if they were storing data for me.
If you are wharehousing data, you dont just let your customer's customer come in, look around, and take whatever they want. Even if they have a sob story.
You ask for a court order with specifics.
How about before the company went out of business? Wasn’t there an avenue for the CEO to send a letter to Iron Mountain mapping the data and its owners or make an arrangement to legally transfer the data or something?
It's unfair when you do the best you can and suddenly you have to talk to lawyers.