This is great; however, folks can still securely store data on cloud services. They just need to take a Trust No one (TNO) approach and encrypt their data to disk. For example you can use TrueCrypt and create/mount a drive volume that is fully encrypted while synced across a file share storage/sync service like DropBox. The only downside is that you have to install the TrueCrypt application on your client device, whi…
Another downside of using Truecrypt is that when you make a change in your volume, the whole volume file gets reuploaded to your storage/sync service. A better solution is to use .sparsebundles (Mac only) or something like BoxCryptor/encfs that encrypts files in the volume individually
The real problem with using a Truecrypt volume on Dropbox is concurrent changes to the same volume. It happens if you mount the Truecrypt volume on 2 machines at the same time. It will mess up badly.