People who know me well know that I do not easily entrust my data to the cloud. I find that even with the best of intentions, the risk of accidental data leakage is just to great. There has been a recent case proving that my fears are founded.
A bug in Gmail allowed students at some schools to read each other’s emails. I don’t know about you but I’d rather not have other people read my emails. (Yes, I know the vast majority of emails are transfered in plain text. I does not entail that it is okay for my colleagues to be able to access my mail folders.)