Here are two terms and conditions excerpts from a couple of popular cloud storage vendors. I'm not trying to spread FUD because cloud computing really is a fantastic concept. I'm just offering fair warning for you to do your own research and take responsibility for your data.
Displayed very clearly, these two excerpts make it pretty clear the liability is on you, no matter what happens to your data.
"CARBONITE DOES NOT WARRANT THAT THE CARBONITE PRODUCTS, THIRD PARTY COMPONENTS, OR BETA SOFTWARE WILL MEET YOUR REQUIREMENTS, OR THAT THE OPERATION OF THE CARBONITE PRODUCTS, THIRD PARTY COMPONENTS, OR BETA SOFTWARE WILL BE UNINTERRUPTED OR ERROR-FREE, OR THAT DEFECTS IN THE CARBONITE PRODUCTS, THIRD PARTY COMPONENTS, OR BETA SOFTWARE WILL BE CORRECTED, OR THAT ENCRYPTION ALGORITHIMS, ASSOCIATED KEYS AND OTHER SECURITY MEASURES WILL BE SECURE OR EFFECTIVE."
From Amazon Web Services:
"THE SERVICE OFFERINGS ARE PROVIDED “AS IS.” WE AND OUR AFFILIATES AND LICENSORS MAKE NO REPRESENTATIONS OR WARRANTIES OF ANY KIND, WHETHER EXPRESS, IMPLIED, STATUTORY OR OTHERWISE REGARDING THE SERVICE OFFERINGS OR THE THIRD PARTY CONTENT, INCLUDING ANY WARRANTY THAT THE SERVICE OFFERINGS OR THIRD PARTY CONTENT WILL BE UNINTERRUPTED, ERROR FREE OR FREE OF HARMFUL COMPONENTS, OR THAT ANY CONTENT, INCLUDING YOUR CONTENT OR THE THIRD PARTY CONTENT, WILL BE SECURE OR NOT OTHERWISE LOST OR DAMAGED."