What you might learn from a casual reading of such agreements could be very enlightening. Take this comparison of the service terms for Google Drive and Dropbox.

Both cloud storage providers emphatically state that any content you store with them belongs to you. No doubt both services have learned to say that from the of rival Facebook

"Some of our Services allow you to submit content," explains. "You retain ownership of any intellectual property rights that you hold in that content. In short, what belongs to you stays yours."

While you own content uploaded to Google Drive, the act of storing it with Google has some strings attached. "When you upload or otherwise submit content to our Services, you give Google (and those we work with) a worldwide license to use, host, store, reproduce, modify, create derivative works..., communicate, publish, publicly perform, publicly display and distribute such content," Google's agreement states.