I'm not a lawyer but technically most if not all cloud providers, specific to AI ("neo-cloud") or not, to provide Customer-managed encryption keys (CMEK) as someone else pointed out.

That being said if I were to be in such a situation, and if somehow the guarantees wouldn't be enough then I'd definitely expect to have the budget to build my own data center with GB300 or TPUs. I can't imagine that running it on a Mac Studio.