For digital services like cloud storage, you can use cryptography. Have the storage provider give a cryptograpic proof that they are still in possession of the

For digital services like cloud storage, you can use cryptography. Have the storage provider give a cryptograpic proof that they are still in possession of the data that is under contract, and you don't need a third party. Either they are online and can build the proof, or they are going to get hit with a penalty for dropping their end of the contract.