* Privacy — Someone else hosting and serving your data could be approached by the U.S. government to access and search that data without your knowledge or approval. Current indications are that they would be obligated to comply.

* Compliance — You are probably already aware of the regulations that apply to your business. In theory, cloud service providers can meet the same level of compliance for data stored in the cloud but, because most of these services are young, you'll need to take extra care.

* Data ownership — Do you still own your data once it goes into the cloud? You may think the answer to this question is obvious, but the recent flap over Facebook's attempt to change its terms of use suggests that the question is worth a second look.

* Data Mobility — Can you share data between cloud services? If you terminate a cloud relationship can you get your data back? What format will it be in? How can you be sure all other copies are destroyed?

For a service that's going to be critical to your company, the best advice is to ask a lot of questions and get all commitments in writing.